Date::Parse -- four digit years translated to the future [rt.cpan.org #105031]

Migrated from rt.cpan.org#105031 (status was 'new')

Requestors:

revhippie@gmail.com

From revhippie@gmail.com on 2015-06-07 02:47:12 :

I think bug #53413 may have been misunderstood.

After str2time uses strptime to break up the incoming date, it passes
the result (with $year - 1900) to Time::Local::timelocal.  timelocal
uses a sliding window to determine if the year should be 19xx or 20xx,
completely throwing away the *known* four-digit year that we sent to
str2time.

For example:

    say "$_\t", str2time($_) for qw(
        1965-12-31
        1966-01-01
    );

generates:

    1965-12-31  3029464800 # 2065
    1966-01-01  -126208800 # 1966

(This will produce different results if run a year from now -- they'll
both come back in the 21st century instead of the 20th.)

This might not be a bug, but it's certainly surprising behavior.  The
window is documented in Time::Local, but I think Date::Parse shouldn't
expose end-users to that oddity.  (Perhaps by adding 1900 to the
strpdate output if it notices it's been passed a complete year.)

(The Date::Parse documentation refers to an early limit as 1901-12-17
00:00:00 GMT, which is currently about fifty years off.)

https://metacpan.org/pod/Time::Local#Year-Value-Interpretation

My apologies if I appear to be beating a dead horse.

--
Jim Davis

-- 
Jim Davis

atoomic / perl-TimeDate

Date::Parse -- four digit years translated to the future [rt.cpan.org #105031] #17