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m3doune/date_util.erl

Forked from zaphar/date_util.erl
Created January 14, 2020 16:15
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Revisions

  1. @zaphar zaphar created this gist May 1, 2009.
    114 changes: 114 additions & 0 deletions date_util.erl
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,114 @@
    -module(date_util).
    -compile(export_all).

    epoch() ->
    now_to_seconds(now())
    .

    epoch_hires() ->
    now_to_seconds_hires(now())
    .

    now_to_seconds({Mega, Sec, _}) ->
    (Mega * 1000000) + Sec
    .

    now_to_milliseconds({Mega, Sec, Micro}) ->
    now_to_seconds({Mega, Sec, Micro}) * 1000
    .

    now_to_seconds_hires({Mega, Sec, Micro}) ->
    now_to_seconds({Mega, Sec, Micro}) + (Micro / 1000000)
    .

    now_to_milliseconds_hires({Mega, Sec, Micro}) ->
    now_to_seconds_hires({Mega, Sec, Micro}) * 1000
    .

    epoch_gregorian_seconds() ->
    calendar:datetime_to_gregorian_seconds({{1970,1,1}, {0,0,0}})
    .

    now_to_gregorian_seconds() ->
    epoch_to_gregorian_seconds(now())
    .

    epoch_to_gregorian_seconds({Mega, Sec, Micro}) ->
    epoch_to_gregorian_seconds(now_to_seconds({Mega, Sec, Micro}));
    epoch_to_gregorian_seconds(Now) ->
    EpochSecs = epoch_gregorian_seconds()
    , Now + EpochSecs
    .

    gregorian_seconds_to_epoch(Secs) ->
    EpochSecs = epoch_gregorian_seconds()
    , Secs - EpochSecs
    .

    date_to_epoch(Date) ->
    datetime_to_epoch({Date, {0,0,0} })
    .

    datetime_to_epoch({Date, Time}) ->
    gregorian_seconds_to_epoch(
    calendar:datetime_to_gregorian_seconds({Date, Time}))
    .

    is_older_by(T1, T2, {days, N}) ->
    N1 = day_difference(T1, T2)
    , case N1 of
    N2 when (-N < N2) ->
    true;
    _ ->
    false
    end
    .

    is_sooner_by(T1, T2, {days, N}) ->
    case day_difference(T1, T2) of
    N1 when N > N1 ->
    true;
    _ ->
    false
    end
    .

    is_time_older_than({Date, Time}, Mark) ->
    is_time_older_than(calendar:datetime_to_gregorian_seconds({Date, Time})
    , Mark);
    is_time_older_than(Time, {DateMark, TimeMark}) ->
    is_time_older_than(Time
    , calendar:datetime_to_gregorian_seconds({DateMark, TimeMark}));
    is_time_older_than(Time, Mark) when is_integer(Time), is_integer(Mark) ->
    Time < Mark
    .

    day_difference({D1, _}, D2) ->
    day_difference(D1, D2);
    day_difference(D1, {D2, _}) ->
    day_difference(D1, D2);
    day_difference(D1, D2) ->
    Days1 = calendar:date_to_gregorian_days(D1)
    , Days2 = calendar:date_to_gregorian_days(D2)
    , Days1 - Days2
    .

    is_time_sooner_than({Date, Time}, Mark) ->
    is_time_sooner_than(calendar:datetime_to_gregorian_seconds({Date, Time})
    , Mark);
    is_time_sooner_than(Time, {DateMark, TimeMark}) ->
    is_time_sooner_than(Time
    , calendar:datetime_to_gregorian_seconds({DateMark, TimeMark}));
    is_time_sooner_than(Time, Mark) when is_integer(Time), is_integer(Mark) ->
    Time > Mark
    .

    subtract(Date, {days, N}) ->
    New = calendar:date_to_gregorian_days(Date) - N
    , calendar:gregorian_days_to_date(New)
    .

    add(Date, {days, N}) ->
    New = calendar:date_to_gregorian_days(Date) + N
    , calendar:gregorian_days_to_date(New)
    .