I don't think the behavior of that code changes. (t.Hour, etc operate on wall time; t.Add operates on both wall and monotonic time.)
If I wanted to truncate times to hours, though, I would write code like this: https://play.golang.org/p/el8hUeXpWK On Mon, Feb 27, 2017 at 3:25 AM, Olivier Mengué <olivier.men...@gmail.com> wrote: > Hi, > > I wrote a library that allows to compute the hour/day/week/month/year bounds > in the location of a given time.Time value. This deals with wall clock, not > monotonic clock. > I just read the monotonic clock proposal at > https://github.com/golang/proposal/blob/master/design/12914-monotonic.md > I fear that my code may be affected by the monotonic clock change. > > Here is the critical part for which I would like to be sure that > computations occurs only on wall clock time, even if given time.Now(). > > // hourBegin returns the time of the beginning of the hour in the same > timezone > // This is not always the same as t.Truncate(time.Hour) > func hourBegin(t time.Time) time.Time { > h := t.Hour() > for { > t = t.Add(-durationFromHourBegin(t)) > r := t.Add(-time.Nanosecond) > if r.Hour() != h { > return t > } > t = r > } > } > > func durationFromHourBegin(t time.Time) time.Duration { > return (time.Duration(t.Minute())*time.Minute + > time.Duration(t.Second())*time.Second + > time.Duration(t.Nanosecond())*time.Nanosecond) > } > > > > func hourNext(t time.Time) time.Time { > h := t.Hour() > for { > t = t.Add(time.Hour - durationFromHourBegin(t)) > if t.Hour() != h { > return t > } > } > } > > > > My use case is only for time Locations in periods where daylight change > occur only of whole hours, but any suggestion for improving the code to be > more generic would be welcome. > > Olivier. > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
