[erlang-questions] How do I compute daytime difference properly?
Mon May 5 20:07:20 CEST 2008
Maybe like this :
delta_date_ms(D1, D2) ->
1000000000 * abs(element(1, D1) - element(1, D2)) + 1000 *
abs(element(2, D1) - element(2, D2)) + trunc(abs(element(3, D1) -
element(3, D2)) / 1000).
On Sat, May 3, 2008 at 9:10 PM, Igor Ribeiro Sucupira <> wrote:
> I think there's no easier way of doing that.
> 2008/5/3 Kirill Zaborski <>:
> > Reading calendar module documentation I see the note:
> > "For computing differences between epochs in time, use the functions
> > counting gregorian days or seconds. If epochs are given as local time, they
> > must be converted to universal time, in order to get the correct value of
> > the elapsed time between epochs. Use of the function time_difference/2 is
> > discouraged."
> > But it's not quite clear to me...
> > E.g. I have 2 values LocalTime1 and LocalTime2 which are somewhat like
> > tuples erlang:localtime/0 and need to compute time difference e.g. in
> > seconds. So should I then convert this values to UTC and then use
> > calendar:datetime_to_gregorian_seconds/1 and then do the subtraction?
> > Or maybe there is some easier way?
> > Best regards,
> > Kirill.
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