Add RFC822 formats as named constants.

Make sure to print a time zone when formatting even if none is defined.
Add a comment introducing lookupTimezone (not lookupTimeZone).

Fixes isse 577.

R=rsc
CC=golang-dev
https://golang.org/cl/196090

diff --git a/src/pkg/time/format.go b/src/pkg/time/format.go
index 22d92ebdbe0289a8c50a66049ea08e57577ceab4..2c6406ebc961a8e5b5c610b7e34e2dd259bee7d8 100644 (file)
--- a/src/pkg/time/format.go
+++ b/src/pkg/time/format.go
@@ -28,9 +28,12 @@ const (
        ANSIC    = "Mon Jan _2 15:04:05 2006"
        UnixDate = "Mon Jan _2 15:04:05 MST 2006"
        RubyDate = "Mon Jan 02 15:04:05 -0700 2006"
-       RFC850   = "Monday, 02-Jan-06 15:04:05 MST"
-       RFC1123  = "Mon, 02 Jan 2006 15:04:05 MST"
-       Kitchen  = "3:04PM"
+       RFC822   = "02 Jan 06 1504 MST"
+       // RFC822 with Zulu time.
+       RFC822Z = "02 Jan 06 1504 -0700"
+       RFC850  = "Monday, 02-Jan-06 15:04:05 MST"
+       RFC1123 = "Mon, 02 Jan 2006 15:04:05 MST"
+       Kitchen = "3:04PM"
        // Special case: use Z to get the time zone formatted according to ISO 8601,
        // which is -0700 or Z for UTC
        ISO8601 = "2006-01-02T15:04:05Z"
@@ -209,7 +212,7 @@ func (t *Time) Format(layout string) string {
                case stdISO8601TZ, stdNumTZ:
                        // Ugly special case.  We cheat and take "Z" to mean "the time
                        // zone as formatted for ISO 8601".
-                       zone := t.ZoneOffset / 60 // conver to minutes
+                       zone := t.ZoneOffset / 60 // convert to minutes
                        if p == stdISO8601TZ && t.ZoneOffset == 0 {
                                p = "Z"
                        } else {
@@ -248,7 +251,21 @@ func (t *Time) Format(layout string) string {
                                p = "am"
                        }
                case stdTZ:
-                       p = t.Zone
+                       if t.Zone != "" {
+                               p = t.Zone
+                       } else {
+                               // No time zone known for this time, but we must print one.
+                               // Use the -0700 format.
+                               zone := t.ZoneOffset / 60 // convert to minutes
+                               if zone < 0 {
+                                       p = "-"
+                                       zone = -zone
+                               } else {
+                                       p = "+"
+                               }
+                               p += zeroPad(zone / 60)
+                               p += zeroPad(zone % 60)
+                       }
                }
                b.WriteString(p)
        }

diff --git a/src/pkg/time/time_test.go b/src/pkg/time/time_test.go
index 2fb5b668ca6a4a4f1c428de6f676bf54c352230e..ab0da37e983e87742595be53f14f1ce476e90b8e 100644 (file)
--- a/src/pkg/time/time_test.go
+++ b/src/pkg/time/time_test.go
@@ -133,6 +133,7 @@ var formatTests = []FormatTest{
        FormatTest{"ANSIC", ANSIC, "Thu Feb  4 21:00:57 2010"},
        FormatTest{"UnixDate", UnixDate, "Thu Feb  4 21:00:57 PST 2010"},
        FormatTest{"RubyDate", RubyDate, "Thu Feb 04 21:00:57 -0800 2010"},
+       FormatTest{"RFC822", RFC822, "04 Feb 10 2100 PST"},
        FormatTest{"RFC850", RFC850, "Thursday, 04-Feb-10 21:00:57 PST"},
        FormatTest{"RFC1123", RFC1123, "Thu, 04 Feb 2010 21:00:57 PST"},
        FormatTest{"ISO8601", ISO8601, "2010-02-04T21:00:57-0800"},
@@ -286,6 +287,20 @@ func TestParseErrors(t *testing.T) {
        }
 }
 
+// Check that a time without a Zone still produces a (numeric) time zone
+// when formatted with MST as a requested zone.
+func TestMissingZone(t *testing.T) {
+       time, err := Parse(RubyDate, "Tue Feb 02 16:10:03 -0500 2006")
+       if err != nil {
+               t.Fatal("error parsing date:", err)
+       }
+       expect := "Tue Feb  2 16:10:03 -0500 2006" // -0500 not EST
+       str := time.Format(UnixDate)               // uses MST as its time zone
+       if str != expect {
+               t.Errorf("expected %q got %q", expect, str)
+       }
+}
+
 func BenchmarkSeconds(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Seconds()

diff --git a/src/pkg/time/zoneinfo.go b/src/pkg/time/zoneinfo.go
index 98d816b101586b801ef91a6420b01cff8c8f64a7..7884898f72d20172bb0b85d211e7105b9e9fcf7f 100644 (file)
--- a/src/pkg/time/zoneinfo.go
+++ b/src/pkg/time/zoneinfo.go
@@ -221,6 +221,7 @@ func setupZone() {
        }
 }
 
+// Look up the correct time zone (daylight savings or not) for the given unix time, in the current location.
 func lookupTimezone(sec int64) (zone string, offset int) {
        once.Do(setupZone)
        if len(zones) == 0 {