@node ax_prog_date
@unnumberedsec ax_prog_date

@majorheading Synopsis

@smallexample
AX_PROG_DATE()
@end smallexample

@majorheading Description

This macro tries to determine the type of the date (1) command and some
of its non-standard capabilities.

The type is determined as follow:

@smallexample
  * If the version string contains "GNU", then:
    - The variable ax_cv_prog_date_gnu is set to "yes".
    - The variable ax_cv_prog_date_type is set to "gnu".
@end smallexample

@smallexample
  * If date supports the "-v 1d" option, then:
    - The variable ax_cv_prog_date_bsd is set to "yes".
    - The variable ax_cv_prog_date_type is set to "bsd".
@end smallexample

@smallexample
  * If both previous checks fail, then:
    - The variable ax_cv_prog_date_type is set to "unknown".
@end smallexample

The following capabilities of GNU date are checked:

@smallexample
  * If date supports the --date arg option, then:
    - The variable ax_cv_prog_date_gnu_date is set to "yes".
@end smallexample

@smallexample
  * If date supports the --utc arg option, then:
    - The variable ax_cv_prog_date_gnu_utc is set to "yes".
@end smallexample

The following capabilities of BSD date are checked:

@smallexample
  * If date supports the -v 1d  option, then:
    - The variable ax_cv_prog_date_bsd_adjust is set to "yes".
@end smallexample

@smallexample
  * If date supports the -r arg option, then:
    - The variable ax_cv_prog_date_bsd_date is set to "yes".
@end smallexample

All the aforementioned variables are set to "no" before a check is
performed.

@majorheading Source Code

Download the
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_prog_date.m4,latest
version of @file{ax_prog_date.m4}} or browse
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_prog_date.m4,the
macro's revision history}.

@majorheading License

@w{Copyright @copyright{} 2017 Enrico M. Crisostomo @email{enrico.m.crisostomo@@gmail.com}}

This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.

You should have received a copy of the GNU General Public License along
with this program. If not, see <http://www.gnu.org/licenses/>.

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