Merge pull request #7894 from hashicorp/b-cronexpr-dst-fix

Fix Daylight saving transition handling
2026-01-04 01:15:43 +03:00 · 2020-05-12 16:36:11 -04:00
parent 5bc75fdbde 1e7ebf5f55
commit cf47153b52
14 changed files with 470 additions and 273 deletions
--- a/api/go.mod
+++ b/api/go.mod
@@ -5,8 +5,8 @@ go 1.12
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/docker/go-units v0.3.3
-	github.com/gorhill/cronexpr v0.0.0-20180427100037-88b0669f7d75
 	github.com/gorilla/websocket v1.4.1
+	github.com/hashicorp/cronexpr v1.1.0
 	github.com/hashicorp/go-cleanhttp v0.5.1
 	github.com/hashicorp/go-rootcerts v1.0.2
 	github.com/kr/pretty v0.1.0
--- a/api/go.sum
+++ b/api/go.sum
@@ -4,10 +4,12 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/docker/go-units v0.3.3 h1:Xk8S3Xj5sLGlG5g67hJmYMmUgXv5N4PhkjJHHqrwnTk=
 github.com/docker/go-units v0.3.3/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
-github.com/gorhill/cronexpr v0.0.0-20180427100037-88b0669f7d75 h1:f0n1xnMSmBLzVfsMMvriDyA75NB/oBgILX2GcHXIQzY=
-github.com/gorhill/cronexpr v0.0.0-20180427100037-88b0669f7d75/go.mod h1:g2644b03hfBX9Ov0ZBDgXXens4rxSxmqFBbhvKv2yVA=
 github.com/gorilla/websocket v1.4.1 h1:q7AeDBpnBk8AogcD4DSag/Ukw/KV+YhzLj2bP5HvKCM=
 github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/hashicorp/cronexpr v0.0.0-20200507212857-921335d977b6 h1:hMI/9mZ+/xcLlMG1VjW/KwScPOJRDyY30b4aUzxfz0g=
+github.com/hashicorp/cronexpr v0.0.0-20200507212857-921335d977b6/go.mod h1:P4wA0KBl9C5q2hABiMO7cp6jcIg96CDh1Efb3g1PWA4=
+github.com/hashicorp/cronexpr v1.1.0 h1:dnNsWtH0V2ReN7JccYe8m//Bj14+PjJDntR1dz0Cixk=
+github.com/hashicorp/cronexpr v1.1.0/go.mod h1:P4wA0KBl9C5q2hABiMO7cp6jcIg96CDh1Efb3g1PWA4=
 github.com/hashicorp/go-cleanhttp v0.5.1 h1:dH3aiDG9Jvb5r5+bYHsikaOUIpcM0xvgMXVoDkXMzJM=
 github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-rootcerts v1.0.2 h1:jzhAVGtqPKbwpyCPELlgNWhE1znq+qwJtW5Oi2viEzc=
--- a/api/jobs.go
+++ b/api/jobs.go
@@ -7,7 +7,7 @@ import (
 	"strconv"
 	"time"

-	"github.com/gorhill/cronexpr"
+	"github.com/hashicorp/cronexpr"
 )

 const (
@@ -648,9 +648,11 @@ func (p *PeriodicConfig) Canonicalize() {
 // passed time.
 func (p *PeriodicConfig) Next(fromTime time.Time) (time.Time, error) {
 	if *p.SpecType == PeriodicSpecCron {
-		if e, err := cronexpr.Parse(*p.Spec); err == nil {
-			return cronParseNext(e, fromTime, *p.Spec)
+		e, err := cronexpr.Parse(*p.Spec)
+		if err != nil {
+			return time.Time{}, fmt.Errorf("failed parsing cron expression %q: %v", *p.Spec, err)
 		}
+		return cronParseNext(e, fromTime, *p.Spec)
 	}

 	return time.Time{}, nil
@@ -670,6 +672,7 @@ func cronParseNext(e *cronexpr.Expression, fromTime time.Time, spec string) (t t

 	return e.Next(fromTime), nil
 }
+
 func (p *PeriodicConfig) GetLocation() (*time.Location, error) {
 	if p.TimeZone == nil || *p.TimeZone == "" {
 		return time.UTC, nil
--- a/nomad/periodic_test.go
+++ b/nomad/periodic_test.go
@@ -16,6 +16,7 @@ import (
 	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/hashicorp/nomad/testutil"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )

 type MockJobEvalDispatcher struct {
@@ -173,29 +174,22 @@ func TestPeriodicDispatch_Add_UpdateJob(t *testing.T) {
 	t.Parallel()
 	p, _ := testPeriodicDispatcher(t)
 	job := mock.PeriodicJob()
-	if err := p.Add(job); err != nil {
-		t.Fatalf("Add failed %v", err)
-	}
+	err := p.Add(job)
+	require.NoError(t, err)

 	tracked := p.Tracked()
-	if len(tracked) != 1 {
-		t.Fatalf("Add didn't track the job: %v", tracked)
-	}
+	require.Lenf(t, tracked, 1, "did not track the job")

 	// Update the job and add it again.
 	job.Periodic.Spec = "foo"
-	if err := p.Add(job); err != nil {
-		t.Fatalf("Add failed %v", err)
-	}
+	err = p.Add(job)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "failed parsing cron expression")

 	tracked = p.Tracked()
-	if len(tracked) != 1 {
-		t.Fatalf("Add didn't update: %v", tracked)
-	}
+	require.Lenf(t, tracked, 1, "did not update")

-	if !reflect.DeepEqual(job, tracked[0]) {
-		t.Fatalf("Add didn't properly update: got %v; want %v", tracked[0], job)
-	}
+	require.Equalf(t, job, tracked[0], "add did not properly update")
 }

 func TestPeriodicDispatch_Add_Remove_Namespaced(t *testing.T) {
--- a/nomad/structs/structs.go
+++ b/nomad/structs/structs.go
@@ -23,7 +23,7 @@ import (
 	"strings"
 	"time"

-	"github.com/gorhill/cronexpr"
+	"github.com/hashicorp/cronexpr"
 	"github.com/hashicorp/go-msgpack/codec"
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/go-version"
@@ -4424,9 +4424,11 @@ func CronParseNext(e *cronexpr.Expression, fromTime time.Time, spec string) (t t
 func (p *PeriodicConfig) Next(fromTime time.Time) (time.Time, error) {
 	switch p.SpecType {
 	case PeriodicSpecCron:
-		if e, err := cronexpr.Parse(p.Spec); err == nil {
-			return CronParseNext(e, fromTime, p.Spec)
+		e, err := cronexpr.Parse(p.Spec)
+		if err != nil {
+			return time.Time{}, fmt.Errorf("failed parsing cron expression: %q: %v", p.Spec, err)
 		}
+		return CronParseNext(e, fromTime, p.Spec)
 	case PeriodicSpecTest:
 		split := strings.Split(p.Spec, ",")
 		if len(split) == 1 && split[0] == "" {
--- a/nomad/structs/structs_periodic_test.go
+++ b/nomad/structs/structs_periodic_test.go
@@ -0,0 +1,284 @@
+package structs
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPeriodicConfig_DSTChange_Transitions(t *testing.T) {
+	locName := "America/Los_Angeles"
+	loc, err := time.LoadLocation(locName)
+	require.NoError(t, err)
+
+	cases := []struct {
+		name     string
+		pattern  string
+		initTime time.Time
+		expected []time.Time
+	}{
+		{
+			"normal time",
+			"0 2 * * * 2019",
+			time.Date(2019, time.February, 7, 1, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.February, 7, 2, 0, 0, 0, loc),
+				time.Date(2019, time.February, 8, 2, 0, 0, 0, loc),
+				time.Date(2019, time.February, 9, 2, 0, 0, 0, loc),
+			},
+		},
+		{
+			"Spring forward but not in switch time",
+			"0 4 * * * 2019",
+			time.Date(2019, time.March, 9, 1, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.March, 9, 4, 0, 0, 0, loc),
+				time.Date(2019, time.March, 10, 4, 0, 0, 0, loc),
+				time.Date(2019, time.March, 11, 4, 0, 0, 0, loc),
+			},
+		},
+		{
+			"Spring forward at a skipped time odd",
+			"2 2 * * * 2019",
+			time.Date(2019, time.March, 9, 1, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.March, 9, 2, 2, 0, 0, loc),
+				// no time in March 10!
+				time.Date(2019, time.March, 11, 2, 2, 0, 0, loc),
+				time.Date(2019, time.March, 12, 2, 2, 0, 0, loc),
+			},
+		},
+		{
+			"Spring forward at a skipped time",
+			"1 2 * * * 2019",
+			time.Date(2019, time.March, 9, 1, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.March, 9, 2, 1, 0, 0, loc),
+				// no time in March 8!
+				time.Date(2019, time.March, 11, 2, 1, 0, 0, loc),
+				time.Date(2019, time.March, 12, 2, 1, 0, 0, loc),
+			},
+		},
+		{
+			"Spring forward at a skipped time boundary",
+			"0 2 * * * 2019",
+			time.Date(2019, time.March, 9, 1, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.March, 9, 2, 0, 0, 0, loc),
+				// no time in March 8!
+				time.Date(2019, time.March, 11, 2, 0, 0, 0, loc),
+				time.Date(2019, time.March, 12, 2, 0, 0, 0, loc),
+			},
+		},
+		{
+			"Spring forward at a boundary of repeating time",
+			"0 1 * * * 2019",
+			time.Date(2019, time.March, 9, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.March, 9, 1, 0, 0, 0, loc),
+				time.Date(2019, time.March, 10, 0, 0, 0, 0, loc).Add(1 * time.Hour),
+				time.Date(2019, time.March, 11, 1, 0, 0, 0, loc),
+				time.Date(2019, time.March, 12, 1, 0, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: before transition",
+			"30 0 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc),
+				time.Date(2019, time.November, 4, 0, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 0, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 0, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: after transition",
+			"30 3 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 4, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 3, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: after transition starting in repeated span before",
+			"30 3 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 10, 0, 0, loc).Add(1 * time.Hour),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 4, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 3, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: after transition starting in repeated span after",
+			"30 3 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 10, 0, 0, loc).Add(2 * time.Hour),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 4, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 3, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 3, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: in repeated region",
+			"30 1 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc).Add(1 * time.Hour),
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc).Add(2 * time.Hour),
+				time.Date(2019, time.November, 4, 1, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 1, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 1, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: in repeated region boundary",
+			"0 1 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 0, 0, 0, 0, loc).Add(1 * time.Hour),
+				time.Date(2019, time.November, 3, 0, 0, 0, 0, loc).Add(2 * time.Hour),
+				time.Date(2019, time.November, 4, 1, 0, 0, 0, loc),
+				time.Date(2019, time.November, 5, 1, 0, 0, 0, loc),
+				time.Date(2019, time.November, 6, 1, 0, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: in repeated region boundary 2",
+			"0 2 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 0, 0, 0, 0, loc).Add(3 * time.Hour),
+				time.Date(2019, time.November, 4, 2, 0, 0, 0, loc),
+				time.Date(2019, time.November, 5, 2, 0, 0, 0, loc),
+				time.Date(2019, time.November, 6, 2, 0, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: in repeated region, starting from within region",
+			"30 1 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 40, 0, 0, loc).Add(1 * time.Hour),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc).Add(2 * time.Hour),
+				time.Date(2019, time.November, 4, 1, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 1, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 1, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: in repeated region, starting from within region 2",
+			"30 1 * * * 2019",
+			time.Date(2019, time.November, 3, 0, 40, 0, 0, loc).Add(2 * time.Hour),
+			[]time.Time{
+				time.Date(2019, time.November, 4, 1, 30, 0, 0, loc),
+				time.Date(2019, time.November, 5, 1, 30, 0, 0, loc),
+				time.Date(2019, time.November, 6, 1, 30, 0, 0, loc),
+			},
+		},
+		{
+			"Fall back: wildcard",
+			"30 * * * * 2019",
+			time.Date(2019, time.November, 3, 0, 0, 0, 0, loc),
+			[]time.Time{
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc),
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc).Add(1 * time.Hour),
+				time.Date(2019, time.November, 3, 0, 30, 0, 0, loc).Add(2 * time.Hour),
+				time.Date(2019, time.November, 3, 2, 30, 0, 0, loc),
+			},
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			p := &PeriodicConfig{
+				Enabled:  true,
+				SpecType: PeriodicSpecCron,
+				Spec:     c.pattern,
+				TimeZone: locName,
+			}
+			p.Canonicalize()
+
+			starting := c.initTime
+			for _, next := range c.expected {
+				n, err := p.Next(starting)
+				assert.NoError(t, err)
+				assert.Equalf(t, next, n, "next time of %v", starting)
+
+				starting = next
+			}
+		})
+	}
+}
+
+func TestPeriodConfig_DSTSprintForward_Property(t *testing.T) {
+	locName := "America/Los_Angeles"
+	loc, err := time.LoadLocation(locName)
+	require.NoError(t, err)
+
+	cronExprs := []string{
+		"* * * * *",
+		"0 2 * * *",
+		"* 1 * * *",
+	}
+
+	times := []time.Time{
+		// spring forward
+		time.Date(2019, time.March, 11, 0, 0, 0, 0, loc),
+		time.Date(2019, time.March, 10, 0, 0, 0, 0, loc),
+		time.Date(2019, time.March, 11, 0, 0, 0, 0, loc),
+
+		// leap backwards
+		time.Date(2019, time.November, 4, 0, 0, 0, 0, loc),
+		time.Date(2019, time.November, 5, 0, 0, 0, 0, loc),
+		time.Date(2019, time.November, 6, 0, 0, 0, 0, loc),
+	}
+
+	testSpan := 4 * time.Hour
+
+	testCase := func(t *testing.T, cronExpr string, init time.Time) {
+		p := &PeriodicConfig{
+			Enabled:  true,
+			SpecType: PeriodicSpecCron,
+			Spec:     cronExpr,
+			TimeZone: "America/Los_Angeles",
+		}
+		p.Canonicalize()
+
+		lastNext := init
+		for start := init; start.Before(init.Add(testSpan)); start = start.Add(1 * time.Minute) {
+			next, err := p.Next(start)
+			require.NoError(t, err)
+			require.Truef(t, next.After(start),
+				"next(%v) = %v is not after init time", start, next)
+
+			if start.Before(lastNext) {
+				require.Equalf(t, lastNext, next, "next(%v) = %v is earlier than previously known next %v",
+					start, next, lastNext)
+			}
+			if strings.HasPrefix(cronExpr, "* * ") {
+				require.Equalf(t, next.Sub(start), 1*time.Minute,
+					"next(%v) = %v is the next minute", start, next)
+			}
+
+			lastNext = next
+		}
+	}
+
+	for _, cron := range cronExprs {
+		for _, startTime := range times {
+			t.Run(fmt.Sprintf("%v: %v", cron, startTime), func(t *testing.T) {
+				testCase(t, cron, startTime)
+			})
+		}
+	}
+}
--- a/nomad/structs/structs_test.go
+++ b/nomad/structs/structs_test.go
@@ -2903,45 +2903,42 @@ func TestPeriodicConfig_ValidCron(t *testing.T) {
 }

 func TestPeriodicConfig_NextCron(t *testing.T) {
-	require := require.New(t)
-
-	type testExpectation struct {
-		Time     time.Time
-		HasError bool
-		ErrorMsg string
-	}
-
 	from := time.Date(2009, time.November, 10, 23, 22, 30, 0, time.UTC)
-	specs := []string{"0 0 29 2 * 1980",
-		"*/5 * * * *",
-		"1 15-0 * * 1-5"}
-	expected := []*testExpectation{
+
+	cases := []struct {
+		spec     string
+		nextTime time.Time
+		errorMsg string
+	}{
 		{
-			Time:     time.Time{},
-			HasError: false,
+			spec:     "0 0 29 2 * 1980",
+			nextTime: time.Time{},
 		},
 		{
-			Time:     time.Date(2009, time.November, 10, 23, 25, 0, 0, time.UTC),
-			HasError: false,
+			spec:     "*/5 * * * *",
+			nextTime: time.Date(2009, time.November, 10, 23, 25, 0, 0, time.UTC),
 		},
 		{
-			Time:     time.Time{},
-			HasError: true,
-			ErrorMsg: "failed parsing cron expression",
+			spec:     "1 15-0 *",
+			nextTime: time.Time{},
+			errorMsg: "failed parsing cron expression",
 		},
 	}

-	for i, spec := range specs {
-		p := &PeriodicConfig{Enabled: true, SpecType: PeriodicSpecCron, Spec: spec}
-		p.Canonicalize()
-		n, err := p.Next(from)
-		nextExpected := expected[i]
+	for i, c := range cases {
+		t.Run(fmt.Sprintf("case: %d: %s", i, c.spec), func(t *testing.T) {
+			p := &PeriodicConfig{Enabled: true, SpecType: PeriodicSpecCron, Spec: c.spec}
+			p.Canonicalize()
+			n, err := p.Next(from)

-		require.Equal(nextExpected.Time, n)
-		require.Equal(err != nil, nextExpected.HasError)
-		if err != nil {
-			require.True(strings.Contains(err.Error(), nextExpected.ErrorMsg))
-		}
+			require.Equal(t, c.nextTime, n)
+			if c.errorMsg == "" {
+				require.NoError(t, err)
+			} else {
+				require.Error(t, err)
+				require.Contains(t, err.Error(), c.errorMsg)
+			}
+		})
 	}
 }

@@ -2963,7 +2960,7 @@ func TestPeriodicConfig_DST(t *testing.T) {
 	p := &PeriodicConfig{
 		Enabled:  true,
 		SpecType: PeriodicSpecCron,
-		Spec:     "0 2 11-12 3 * 2017",
+		Spec:     "0 2 11-13 3 * 2017",
 		TimeZone: "America/Los_Angeles",
 	}
 	p.Canonicalize()
@@ -2973,7 +2970,7 @@ func TestPeriodicConfig_DST(t *testing.T) {

 	// E1 is an 8 hour adjustment, E2 is a 7 hour adjustment
 	e1 := time.Date(2017, time.March, 11, 10, 0, 0, 0, time.UTC)
-	e2 := time.Date(2017, time.March, 12, 9, 0, 0, 0, time.UTC)
+	e2 := time.Date(2017, time.March, 13, 9, 0, 0, 0, time.UTC)

 	n1, err := p.Next(t1)
 	require.Nil(err)
--- a/vendor/github.com/hashicorp/cronexpr/APLv2
+++ b/vendor/github.com/hashicorp/cronexpr/APLv2
--- a/vendor/github.com/hashicorp/cronexpr/GPLv3
+++ b/vendor/github.com/hashicorp/cronexpr/GPLv3
--- a/vendor/github.com/hashicorp/cronexpr/README.md
+++ b/vendor/github.com/hashicorp/cronexpr/README.md
--- a/vendor/github.com/hashicorp/cronexpr/cronexpr.go
+++ b/vendor/github.com/hashicorp/cronexpr/cronexpr.go
@@ -1,6 +1,8 @@
 /*!
 * Copyright 2013 Raymond Hill
 *
+ * Modifications 2020 - HashiCorp
+ *
 * Project: github.com/gorhill/cronexpr
 * File: cronexpr.go
 * Version: 1.0
@@ -160,78 +162,122 @@ func (expr *Expression) Next(fromTime time.Time) time.Time {
 		return fromTime
 	}

-	// Since expr.nextSecond()-expr.nextMonth() expects that the
-	// supplied time stamp is a perfect match to the underlying cron
-	// expression, and since this function is an entry point where `fromTime`
-	// does not necessarily matches the underlying cron expression,
-	// we first need to ensure supplied time stamp matches
-	// the cron expression. If not, this means the supplied time
-	// stamp falls in between matching time stamps, thus we move
-	// to closest future matching immediately upon encountering a mismatching
-	// time stamp.
+	loc := fromTime.Location()
+	t := fromTime.Add(time.Second - time.Duration(fromTime.Nanosecond())*time.Nanosecond)

-	// year
-	v := fromTime.Year()
-	i := sort.SearchInts(expr.yearList, v)
-	if i == len(expr.yearList) {
+WRAP:
+
+	// let's find the next date that satisfies condition
+	v := t.Year()
+	if i := sort.SearchInts(expr.yearList, v); i == len(expr.yearList) {
 		return time.Time{}
-	}
-	if v != expr.yearList[i] {
-		return expr.nextYear(fromTime)
-	}
-	// month
-	v = int(fromTime.Month())
-	i = sort.SearchInts(expr.monthList, v)
-	if i == len(expr.monthList) {
-		return expr.nextYear(fromTime)
-	}
-	if v != expr.monthList[i] {
-		return expr.nextMonth(fromTime)
+	} else if v != expr.yearList[i] {
+		t = time.Date(expr.yearList[i], time.Month(expr.monthList[0]), 1, 0, 0, 0, 0, loc)
 	}

-	expr.actualDaysOfMonthList = expr.calculateActualDaysOfMonth(fromTime.Year(), int(fromTime.Month()))
+	v = int(t.Month())
+	if i := sort.SearchInts(expr.monthList, v); i == len(expr.monthList) {
+		// try again with a new year
+		t = time.Date(t.Year()+1, time.Month(expr.monthList[0]), 1, 0, 0, 0, 0, loc)
+		goto WRAP
+	} else if v != expr.monthList[i] {
+		t = time.Date(t.Year(), time.Month(expr.monthList[i]), 1, 0, 0, 0, 0, loc)
+	}
+
+	expr.actualDaysOfMonthList = expr.calculateActualDaysOfMonth(t.Year(), int(t.Month()))
 	if len(expr.actualDaysOfMonthList) == 0 {
-		return expr.nextMonth(fromTime)
+		t = time.Date(t.Year(), t.Month()+1, 1, 0, 0, 0, 0, loc)
+		goto WRAP
 	}

-	// day of month
-	v = fromTime.Day()
-	i = sort.SearchInts(expr.actualDaysOfMonthList, v)
-	if i == len(expr.actualDaysOfMonthList) {
-		return expr.nextMonth(fromTime)
-	}
-	if v != expr.actualDaysOfMonthList[i] {
-		return expr.nextDayOfMonth(fromTime)
-	}
-	// hour
-	v = fromTime.Hour()
-	i = sort.SearchInts(expr.hourList, v)
-	if i == len(expr.hourList) {
-		return expr.nextDayOfMonth(fromTime)
-	}
-	if v != expr.hourList[i] {
-		return expr.nextHour(fromTime)
-	}
-	// minute
-	v = fromTime.Minute()
-	i = sort.SearchInts(expr.minuteList, v)
-	if i == len(expr.minuteList) {
-		return expr.nextHour(fromTime)
-	}
-	if v != expr.minuteList[i] {
-		return expr.nextMinute(fromTime)
-	}
-	// second
-	v = fromTime.Second()
-	i = sort.SearchInts(expr.secondList, v)
-	if i == len(expr.secondList) {
-		return expr.nextMinute(fromTime)
+	v = t.Day()
+	if i := sort.SearchInts(expr.actualDaysOfMonthList, v); i == len(expr.actualDaysOfMonthList) {
+		t = time.Date(t.Year(), t.Month()+1, 1, 0, 0, 0, 0, loc)
+		goto WRAP
+	} else if v != expr.actualDaysOfMonthList[i] {
+		t = time.Date(t.Year(), t.Month(), expr.actualDaysOfMonthList[i], 0, 0, 0, 0, loc)
+
+		// in San Palo, before 2019, there may be no midnight (or multiple midnights)
+		// due to DST
+		if t.Hour() != 0 {
+			if t.Hour() > 12 {
+				t = t.Add(time.Duration(24-t.Hour()) * time.Hour)
+			} else {
+				t = t.Add(time.Duration(-t.Hour()) * time.Hour)
+			}
+		}
 	}

-	// If we reach this point, there is nothing better to do
-	// than to move to the next second
+	if timeZoneInDay(t) {
+		goto SLOW_CLOCK
+	}

-	return expr.nextSecond(fromTime)
+	// Fast path where hours/minutes behave as expected trivially
+	v = t.Hour()
+	if i := sort.SearchInts(expr.hourList, v); i == len(expr.hourList) {
+		t = time.Date(t.Year(), t.Month(), t.Day()+1, 0, 0, 0, 0, loc)
+		goto WRAP
+	} else if v != expr.hourList[i] {
+		t = time.Date(t.Year(), t.Month(), t.Day(), expr.hourList[i], expr.minuteList[0], expr.secondList[0], 0, loc)
+	}
+
+	v = t.Minute()
+	if i := sort.SearchInts(expr.minuteList, v); i == len(expr.minuteList) {
+		t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour()+1, 0, 0, 0, loc)
+		goto WRAP
+	} else if v != expr.minuteList[i] {
+		t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), expr.minuteList[i], expr.secondList[0], 0, loc)
+	}
+
+	v = t.Second()
+	if i := sort.SearchInts(expr.secondList, v); i == len(expr.secondList) {
+		t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute()+1, 0, 0, loc)
+		goto WRAP
+	} else if v != expr.secondList[i] {
+		t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), expr.secondList[i], 0, loc)
+	}
+
+	return t
+
+SLOW_CLOCK:
+	// daylight saving effect is here, where odd things happen:
+	// An hour may have 60 minutes, 30 minutes or 90 minutes;
+	// partial hours may "repeat"!
+	for !sortContains(expr.hourList, t.Hour()) {
+		hourBefore := t.Hour()
+		t = t.Add(time.Hour)
+		if hourBefore == t.Hour() {
+			t = t.Add(time.Hour)
+		}
+		t = t.Truncate(time.Minute)
+		if t.Minute() != 0 {
+			t = t.Add(-1 * time.Minute * time.Duration(t.Minute()))
+		}
+
+		if t.Hour() == 0 {
+			t = time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, loc)
+			goto WRAP
+		}
+	}
+
+	for !sortContains(expr.minuteList, t.Minute()) {
+		hoursBefore := t.Hour()
+		t = t.Truncate(time.Minute).Add(time.Minute)
+		if hoursBefore != t.Hour() {
+			goto WRAP
+		}
+	}
+
+	v = t.Second()
+	t = t.Truncate(time.Minute)
+	if i := sort.SearchInts(expr.secondList, v); i == len(expr.secondList) {
+		t = t.Add(time.Minute)
+		goto WRAP
+	} else {
+		t = t.Add(time.Duration(expr.secondList[i]) * time.Second)
+	}
+
+	return t
 }

 /******************************************************************************/
@@ -259,7 +305,7 @@ func (expr *Expression) NextN(fromTime time.Time, n uint) []time.Time {
 			if n == 0 {
 				break
 			}
-			fromTime = expr.nextSecond(fromTime)
+			fromTime = expr.Next(fromTime)
 		}
 	}
 	return nextTimes
--- a/vendor/github.com/hashicorp/cronexpr/cronexpr_next.go
+++ b/vendor/github.com/hashicorp/cronexpr/cronexpr_next.go
@@ -1,6 +1,8 @@
 /*!
 * Copyright 2013 Raymond Hill
 *
+ * Modifications 2020 - HashiCorp
+ *
 * Project: github.com/gorhill/cronexpr
 * File: cronexpr_next.go
 * Version: 1.0
@@ -33,160 +35,6 @@ var dowNormalizedOffsets = [][]int{

 /******************************************************************************/

-func (expr *Expression) nextYear(t time.Time) time.Time {
-	// Find index at which item in list is greater or equal to
-	// candidate year
-	i := sort.SearchInts(expr.yearList, t.Year()+1)
-	if i == len(expr.yearList) {
-		return time.Time{}
-	}
-	// Year changed, need to recalculate actual days of month
-	expr.actualDaysOfMonthList = expr.calculateActualDaysOfMonth(expr.yearList[i], expr.monthList[0])
-	if len(expr.actualDaysOfMonthList) == 0 {
-		return expr.nextMonth(time.Date(
-			expr.yearList[i],
-			time.Month(expr.monthList[0]),
-			1,
-			expr.hourList[0],
-			expr.minuteList[0],
-			expr.secondList[0],
-			0,
-			t.Location()))
-	}
-	return time.Date(
-		expr.yearList[i],
-		time.Month(expr.monthList[0]),
-		expr.actualDaysOfMonthList[0],
-		expr.hourList[0],
-		expr.minuteList[0],
-		expr.secondList[0],
-		0,
-		t.Location())
-}
-
-/******************************************************************************/
-
-func (expr *Expression) nextMonth(t time.Time) time.Time {
-	// Find index at which item in list is greater or equal to
-	// candidate month
-	i := sort.SearchInts(expr.monthList, int(t.Month())+1)
-	if i == len(expr.monthList) {
-		return expr.nextYear(t)
-	}
-	// Month changed, need to recalculate actual days of month
-	expr.actualDaysOfMonthList = expr.calculateActualDaysOfMonth(t.Year(), expr.monthList[i])
-	if len(expr.actualDaysOfMonthList) == 0 {
-		return expr.nextMonth(time.Date(
-			t.Year(),
-			time.Month(expr.monthList[i]),
-			1,
-			expr.hourList[0],
-			expr.minuteList[0],
-			expr.secondList[0],
-			0,
-			t.Location()))
-	}
-
-	return time.Date(
-		t.Year(),
-		time.Month(expr.monthList[i]),
-		expr.actualDaysOfMonthList[0],
-		expr.hourList[0],
-		expr.minuteList[0],
-		expr.secondList[0],
-		0,
-		t.Location())
-}
-
-/******************************************************************************/
-
-func (expr *Expression) nextDayOfMonth(t time.Time) time.Time {
-	// Find index at which item in list is greater or equal to
-	// candidate day of month
-	i := sort.SearchInts(expr.actualDaysOfMonthList, t.Day()+1)
-	if i == len(expr.actualDaysOfMonthList) {
-		return expr.nextMonth(t)
-	}
-
-	return time.Date(
-		t.Year(),
-		t.Month(),
-		expr.actualDaysOfMonthList[i],
-		expr.hourList[0],
-		expr.minuteList[0],
-		expr.secondList[0],
-		0,
-		t.Location())
-}
-
-/******************************************************************************/
-
-func (expr *Expression) nextHour(t time.Time) time.Time {
-	// Find index at which item in list is greater or equal to
-	// candidate hour
-	i := sort.SearchInts(expr.hourList, t.Hour()+1)
-	if i == len(expr.hourList) {
-		return expr.nextDayOfMonth(t)
-	}
-
-	return time.Date(
-		t.Year(),
-		t.Month(),
-		t.Day(),
-		expr.hourList[i],
-		expr.minuteList[0],
-		expr.secondList[0],
-		0,
-		t.Location())
-}
-
-/******************************************************************************/
-
-func (expr *Expression) nextMinute(t time.Time) time.Time {
-	// Find index at which item in list is greater or equal to
-	// candidate minute
-	i := sort.SearchInts(expr.minuteList, t.Minute()+1)
-	if i == len(expr.minuteList) {
-		return expr.nextHour(t)
-	}
-
-	return time.Date(
-		t.Year(),
-		t.Month(),
-		t.Day(),
-		t.Hour(),
-		expr.minuteList[i],
-		expr.secondList[0],
-		0,
-		t.Location())
-}
-
-/******************************************************************************/
-
-func (expr *Expression) nextSecond(t time.Time) time.Time {
-	// nextSecond() assumes all other fields are exactly matched
-	// to the cron expression
-
-	// Find index at which item in list is greater or equal to
-	// candidate second
-	i := sort.SearchInts(expr.secondList, t.Second()+1)
-	if i == len(expr.secondList) {
-		return expr.nextMinute(t)
-	}
-
-	return time.Date(
-		t.Year(),
-		t.Month(),
-		t.Day(),
-		t.Hour(),
-		t.Minute(),
-		expr.secondList[i],
-		0,
-		t.Location())
-}
-
-/******************************************************************************/
-
 func (expr *Expression) calculateActualDaysOfMonth(year, month int) []int {
 	actualDaysOfMonthMap := make(map[int]bool)
 	firstDayOfMonth := time.Date(year, time.Month(month), 1, 0, 0, 0, 0, time.UTC)
@@ -290,3 +138,18 @@ func workdayOfMonth(targetDom, lastDom time.Time) int {
 	}
 	return dom
 }
+
+func sortContains(a []int, x int) bool {
+	i := sort.SearchInts(a, x)
+	return i < len(a) && a[i] == x
+}
+
+func timeZoneInDay(t time.Time) bool {
+	if t.Location() == time.UTC {
+		return false
+	}
+
+	_, off := t.AddDate(0, 0, -1).Zone()
+	_, ndoff := t.AddDate(0, 0, 1).Zone()
+	return off != ndoff
+}
--- a/vendor/github.com/hashicorp/cronexpr/cronexpr_parse.go
+++ b/vendor/github.com/hashicorp/cronexpr/cronexpr_parse.go
@@ -1,6 +1,8 @@
 /*!
 * Copyright 2013 Raymond Hill
 *
+ * Modifications 2020 - HashiCorp
+ *
 * Project: github.com/gorhill/cronexpr
 * File: cronexpr_parse.go
 * Version: 1.0
@@ -319,6 +321,10 @@ func (expr *Expression) dowFieldHandler(s string) error {
 		case one:
 			populateOne(expr.daysOfWeek, directive.first)
 		case span:
+			// To properly handle spans that end in 7 (Sunday)
+			if directive.last == 0 {
+				directive.last = 6
+			}
 			populateMany(expr.daysOfWeek, directive.first, directive.last, directive.step)
 		case all:
 			populateMany(expr.daysOfWeek, directive.first, directive.last, directive.step)
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -183,7 +183,6 @@
 		{"path":"github.com/google/go-cmp/cmp/internal/function","checksumSHA1":"kYtvRhMjM0X4bvEjR3pqEHLw1qo=","revision":"d5735f74713c51f7450a43d0a98d41ce2c1db3cb","revisionTime":"2017-09-01T21:42:48Z"},
 		{"path":"github.com/google/go-cmp/cmp/internal/value","checksumSHA1":"f+mgZLvc4VITtMmBv0bmew4rL2Y=","revision":"d5735f74713c51f7450a43d0a98d41ce2c1db3cb","revisionTime":"2017-09-01T21:42:48Z"},
 		{"path":"github.com/googleapis/gax-go/v2","checksumSHA1":"WZoHSeTnVjnPIX2+U1Otst5MUKw=","revision":"bd5b16380fd03dc758d11cef74ba2e3bc8b0e8c2","revisionTime":"2019-05-13T18:38:25Z"},
-		{"path":"github.com/gorhill/cronexpr","checksumSHA1":"m8B3L3qJ3tFfP6BI9pIFr9oal3w=","comment":"1.0.0","origin":"github.com/dadgar/cronexpr","revision":"675cac9b2d182dccb5ba8d5f8a0d5988df8a4394","revisionTime":"2017-09-15T18:30:32Z"},
 		{"path":"github.com/gorilla/context","checksumSHA1":"g/V4qrXjUGG9B+e3hB+4NAYJ5Gs=","revision":"08b5f424b9271eedf6f9f0ce86cb9396ed337a42","revisionTime":"2016-08-17T18:46:32Z"},
 		{"path":"github.com/gorilla/mux","checksumSHA1":"STQSdSj2FcpCf0NLfdsKhNutQT0=","revision":"e48e440e4c92e3251d812f8ce7858944dfa3331c","revisionTime":"2018-08-07T07:52:56Z"},
 		{"path":"github.com/gorilla/websocket","checksumSHA1":"gr0edNJuVv4+olNNZl5ZmwLgscA=","revision":"0ec3d1bd7fe50c503d6df98ee649d81f4857c564","revisionTime":"2019-03-06T00:42:57Z"},
@@ -210,6 +209,7 @@
 		{"path":"github.com/hashicorp/consul/sdk/testutil","checksumSHA1":"BdbalXv3cKiFTZpRCy4fgIzHBEU=","revision":"b137060630b463d7ad5360f0d8f32f9347ae3b7d","revisionTime":"2020-02-13T19:55:27Z"},
 		{"path":"github.com/hashicorp/consul/sdk/testutil/retry","checksumSHA1":"d3PJhffDKar25kzK0iEqssVMkck=","revision":"b137060630b463d7ad5360f0d8f32f9347ae3b7d","revisionTime":"2020-02-13T19:55:27Z"},
 		{"path":"github.com/hashicorp/consul/version","checksumSHA1":"fRbV3oycM2uY4oOkDoSXtP4o6Tc=","revision":"b137060630b463d7ad5360f0d8f32f9347ae3b7d","revisionTime":"2020-02-13T19:55:27Z"},
+		{"path":"github.com/hashicorp/cronexpr","checksumSHA1":"lKpw2wPcDeImWS2fPAzfSJl+Gcc=","revision":"d968249ea977a46db0f3588b5c5e438243cca0cb","revisionTime":"2020-05-08T15:08:16Z","version":"v1.1.0","versionExact":"v1.1.0"},
 		{"path":"github.com/hashicorp/errwrap","checksumSHA1":"cdOCt0Yb+hdErz8NAQqayxPmRsY=","revision":"7554cd9344cec97297fa6649b055a8c98c2a1e55"},
 		{"path":"github.com/hashicorp/go-checkpoint","checksumSHA1":"D267IUMW2rcb+vNe3QU+xhfSrgY=","revision":"1545e56e46dec3bba264e41fde2c1e2aa65b5dd4","revisionTime":"2017-10-09T17:35:28Z"},
 		{"path":"github.com/hashicorp/go-cleanhttp","checksumSHA1":"6ihdHMkDfFx/rJ1A36com2F6bQk=","revision":"a45970658e51fea2c41445ff0f7e07106d007617","revisionTime":"2017-02-11T00:33:01Z"},