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ianlancetaylorianlancetaylor
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time: use extended time format past end of zone transitions
This gives us better expected information for daylight savings time transitions in year 2038 and beyond. Fixes golang#36654 Change-Id: I5a39aed3c40b184e1d7bb7d6ce3aff5307c4c146 Reviewed-on: https://go-review.googlesource.com/c/go/+/215539 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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6 files changed

+523
-22
lines changed

6 files changed

+523
-22
lines changed

‎src/time/export_test.go‎

Lines changed: 31 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -36,12 +36,43 @@ var (
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ReadFile = readFile
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LoadTzinfo = loadTzinfo
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NextStdChunk = nextStdChunk
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Tzset = tzset
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TzsetName = tzsetName
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TzsetOffset = tzsetOffset
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)
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4144
func LoadFromEmbeddedTZData(zone string) (string, error) {
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return loadFromEmbeddedTZData(zone)
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}
4447

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type RuleKind int
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const (
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RuleJulian = RuleKind(ruleJulian)
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RuleDOY = RuleKind(ruleDOY)
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RuleMonthWeekDay = RuleKind(ruleMonthWeekDay)
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)
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type Rule struct {
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Kind RuleKind
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Day int
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Week int
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Mon int
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Time int
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}
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func TzsetRule(s string) (Rule, string, bool) {
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r, rs, ok := tzsetRule(s)
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rr := Rule{
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Kind: RuleKind(r.kind),
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Day: r.day,
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Week: r.week,
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Mon: r.mon,
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Time: r.time,
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}
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return rr, rs, ok
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}
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// StdChunkNames maps from nextStdChunk results to the matched strings.
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var StdChunkNames = map[int]string{
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0: "",

‎src/time/time.go‎

Lines changed: 29 additions & 21 deletions
Original file line numberDiff line numberDiff line change
@@ -1019,6 +1019,34 @@ func daysIn(m Month, year int) int {
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return int(daysBefore[m] - daysBefore[m-1])
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}
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// daysSinceEpoch takes a year and returns the number of days from
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// the absolute epoch to the start of that year.
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// This is basically (year - zeroYear) * 365, but accounting for leap days.
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func daysSinceEpoch(year int) uint64 {
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y := uint64(int64(year) - absoluteZeroYear)
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// Add in days from 400-year cycles.
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n := y / 400
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y -= 400 * n
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d := daysPer400Years * n
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// Add in 100-year cycles.
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n = y / 100
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y -= 100 * n
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d += daysPer100Years * n
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// Add in 4-year cycles.
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n = y / 4
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y -= 4 * n
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d += daysPer4Years * n
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// Add in non-leap years.
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n = y
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d += 365 * n
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return d
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}
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// Provided by package runtime.
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func now() (sec int64, nsec int32, mono int64)
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@@ -1327,28 +1355,8 @@ func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) T
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hour, min = norm(hour, min, 60)
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day, hour = norm(day, hour, 24)
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1330-
y := uint64(int64(year) - absoluteZeroYear)
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// Compute days since the absolute epoch.
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// Add in days from 400-year cycles.
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n := y / 400
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y -= 400 * n
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d := daysPer400Years * n
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// Add in 100-year cycles.
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n = y / 100
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y -= 100 * n
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d += daysPer100Years * n
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// Add in 4-year cycles.
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n = y / 4
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y -= 4 * n
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d += daysPer4Years * n
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// Add in non-leap years.
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n = y
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d += 365 * n
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d := daysSinceEpoch(year)
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// Add in days before this month.
13541362
d += uint64(daysBefore[month-1])

‎src/time/time_test.go‎

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -66,6 +66,13 @@ var nanoutctests = []TimeTest{
6666
var localtests = []TimeTest{
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{0, parsedTime{1969, December, 31, 16, 0, 0, 0, Wednesday, -8 * 60 * 60, "PST"}},
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{1221681866, parsedTime{2008, September, 17, 13, 4, 26, 0, Wednesday, -7 * 60 * 60, "PDT"}},
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{2159200800, parsedTime{2038, June, 3, 11, 0, 0, 0, Thursday, -7 * 60 * 60, "PDT"}},
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{2152173599, parsedTime{2038, March, 14, 1, 59, 59, 0, Sunday, -8 * 60 * 60, "PST"}},
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{2152173600, parsedTime{2038, March, 14, 3, 0, 0, 0, Sunday, -7 * 60 * 60, "PDT"}},
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{2152173601, parsedTime{2038, March, 14, 3, 0, 1, 0, Sunday, -7 * 60 * 60, "PDT"}},
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{2172733199, parsedTime{2038, November, 7, 1, 59, 59, 0, Sunday, -7 * 60 * 60, "PDT"}},
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{2172733200, parsedTime{2038, November, 7, 1, 0, 0, 0, Sunday, -8 * 60 * 60, "PST"}},
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{2172733201, parsedTime{2038, November, 7, 1, 0, 1, 0, Sunday, -8 * 60 * 60, "PST"}},
6976
}
7077

7178
var nanolocaltests = []TimeTest{

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