offset = zone.offset
	start = tx[lo].when
	// end = maintained during the search
	isDST = zone.isDST

	// If we're at the end of the known zone transitions,
	// try the extend string.
	if lo == len(tx)-1 && l.extend != "" {
		if ename, eoffset, estart, eend, eisDST, ok := tzset(l.extend, start, sec); ok {
			return ename, eoffset, estart, eend, eisDST
		}
	}

	return
}

							offset: offset,
							isDST:  isDST,
						}
					}
				}
			}
			break
		}
	}

	return l, nil
}

func findZone(zones []zone, name string, offset int, isDST bool) int {
	for i, z := range zones {
		if z.name == name && z.offset == offset && z.isDST == isDST {
			return i
		}
	}
	return -1
}

	} {
		name, off, start, end, isDST, ok := time.Tzset(test.inStr, test.inEnd, test.inSec)
		if name != test.name || off != test.off || start != test.start || end != test.end || isDST != test.isDST || ok != test.ok {
			t.Errorf("tzset(%q, %d, %d) = %q, %d, %d, %d, %t, %t, want %q, %d, %d, %d, %t, %t", test.inStr, test.inEnd, test.inSec, name, off, start, end, isDST, ok, test.name, test.off, test.start, test.end, test.isDST, test.ok)

	// standard timezone offset
	o, err := atoi(f[1])
	if err != nil {
		return nil, errBadData
	}
	zones[0] = zone{name: f[0], offset: o, isDST: false}

	// alternate timezone offset
	o, err = atoi(f[3])
	if err != nil {
		return nil, errBadData
	}
	zones[1] = zone{name: f[2], offset: o, isDST: true}

	// transition time pairs
	var tx []zoneTrans
	f = f[4:]
	for i := 0; i < len(f); i++ {
		zi := 0
		if i%2 == 0 {

{ .time.wall <type -8>; .time.ext <type -4>; .time.loc <type 14 *<type 15 "time.Location" <type 16 struct { .time.name <type -16>; .time.zone <type 17 [] <type 18 ".time.zone" <type 19 struct { .time.name <type -16>; .time.offset <type -11>; .time.isDST <type -15>; }>>>; .time.tx <type 20 [] <type 21 ".time.zoneTrans" <type 22 struct { .time.when <type -4>; .time.index <type -5>; .time.isstd <type -15>; .time.isutc <type -15>; }>>>; .time.cacheStart <type -4>; .time.cacheEnd <type -4>; .time.cacheZone...

 func (l <type 15>) .time.lookup (sec <type -4>) (name <type -16>, offset <type -11>, isDST <type -15>, start <type -4>, end <type -4>);
 func (l <type 15>) .time.lookupFirstZone () <type -11>;
 func (l <type 15>) .time.firstZoneUsed () <type -15>;
 func (l <type 15>) .time.lookupName (name <type -16>, unix <type -4>) (offset <type -11>, isDST <type -15>, ok <type -15>);
>>; }>
 func (t <type 3>) String () <type -16>;

	// return above.
	std.offset = -int(i.Bias+i.StandardBias) * 60

	dst := &l.zone[1]
	dst.name = dstname
	dst.offset = -int(i.Bias+i.DaylightBias) * 60
	dst.isDST = true

	// Arrange so that d0 is first transition date, d1 second,
	// i0 is index of zone after first transition, i1 second.
	d0 := &i.StandardDate
	d1 := &i.DaylightDate
	i0 := 0
	i1 := 1

func UnixMicro(usec int64) Time {
	return Unix(usec/1e6, (usec%1e6)*1e3)
}

// IsDST reports whether the time in the configured location is in Daylight Savings Time.
func (t Time) IsDST() bool {
	_, _, _, _, isDST := t.loc.lookup(t.Unix())
	return isDST
}

func isLeap(year int) bool {
	return year%4 == 0 && (year%100 != 0 || year%400 == 0)
}

pkg time, const Layout ideal-string
pkg time, func UnixMicro(int64) Time
pkg time, func UnixMilli(int64) Time
pkg time, method (Time) GoString() string
pkg time, method (Time) IsDST() bool
pkg time, method (Time) UnixMicro() int64

		6: {Date(2009, 1, 1, 12, 0, 0, 0, tzFixed), false},
		7: {Date(2009, 6, 1, 12, 0, 0, 0, tzFixed), false},
	}

	for i, tt := range tests {
		got := tt.time.IsDST()
		if got != tt.want {
			t.Errorf("#%d:: (%#v).IsDST()=%t, want %t", i, tt.time.Format(RFC3339), got, tt.want)
		}
	}
}

func TestTimeAddSecOverflow(t *testing.T) {
	// Test it with positive delta.