---+ Package =TWiki::Time=

Time handling functions.


%TOC%

---++ StaticMethod *parseTime* <tt>($szDate,$defaultLocal) -> $iSecs</tt>

Convert string date/time string to seconds since epoch (1970-01-01T00:00:00Z).
   * =$sDate= - date/time string

Handles the following formats:

Default TWiki format
   * 31 Dec 2001 - 23:59

TWiki format without time (defaults to 00:00)
   * 31 Dec 2001

Date seperated by '/', '.' or '-', time with '.' or ':'
Date and time separated by ' ', '.' and/or '-'
   * 2001/12/31 23:59:59
   * 2001.12.31.23.59.59
   * 2001/12/31 23:59
   * 2001.12.31.23.59
   * 2001-12-31 23:59
   * 2001-12-31 - 23:59

ISO format
   * 2001-12-31T23:59:59
ISO dates may have a timezone specifier, either Z or a signed difference
in hh:mm format. For example:
   * 2001-12-31T23:59:59+01:00
   * 2001-12-31T23:59Z
The default timezone is Z, unless $defaultLocal is true in which case
the local timezone will be assumed.

If the date format was not recognised, will return 0.



---++ StaticMethod *formatTime* <tt>($epochSeconds,$formatString,$outputTimeZone) -> $value</tt>

   * =$epochSeconds= epochSecs GMT
   * =$formatString= twiki time date format, default =$day $month $year - $hour:$min=
   * =$outputTimeZone= timezone to display, =gmtime= or =servertime=, default is whatever is set in $TWiki::cfg{DisplayTimeValues}
=$formatString= supports:
   | $seconds | secs |
   | $minutes | mins |
   | $hours | hours |
   | $day | date |
   | $wday | weekday name |
   | $dow | day number (0 = Sunday) |
   | $week | week number |
   | $month | month name |
   | $mo | month number |
   | $year | 4-digit year |
   | $ye | 2-digit year |
   | $http | ful HTTP header format date/time |
   | $email | full email format date/time |
   | $rcs | full RCS format date/time |
   | $epoch | seconds since 1st January 1970 |



---++ StaticMethod *formatDelta* <tt>($s) -> $string</tt>

Format a time in seconds as a string. For example,
"1 day, 3 hours, 2 minutes, 6 seconds"



---++ StaticMethod *parseInterval* <tt>($szInterval) -> [$iSecs,$iSecs]</tt>

Convert string representing a time interval to a pair of integers
representing the amount of seconds since epoch for the start and end
extremes of the time interval.

   * =$szInterval= - time interval string

in yacc syntax, grammar and actions:
<verbatim>
interval ::= date                 { $$.start = fillStart($1); $$.end = fillEnd($1); }
         | date '/' date          { $$.start = fillStart($1); $$.end = fillEnd($3); }
         | 'P' duration '/' date  { $$.start = fillEnd($4)-$2; $$.end = fillEnd($4); }
         | date '/' 'P' duration  { $$.start = fillStart($1); $$.end = fillStart($1)+$4; }
         ;
</verbatim>
an =interval= may be followed by a timezone specification string (this is not supported yet).

=duration= has the form (regular expression):
<verbatim>
   P(<number><nameOfDuration>)+
</verbatim>

nameOfDuration may be one of:
   * y(year), m(month), w(week), d(day), h(hour), M(minute), S(second)

=date= follows ISO8601 and must include hypens.  (any amount of trailing
       elements may be omitted and will be filled in differently on the
       differents ends of the interval as to include the longest possible
       interval):

   * 2001-01-01T00:00:00
   * 2001-12-31T23:59:59

timezone is optional. Default is local time.

If the format is not recognised, will return empty interval [0,0].

TODO: timezone
      testing, especially on non valid strings


