Originally committed as revision 23725 to svn://svn.ffmpeg.org/ffmpeg/trunk
* @param datestr String representing a date or a duration.
* - If a date the syntax is:
* @code
- * [{YYYY-MM-DD|YYYYMMDD}[T|t| ]]{{HH[:MM[:SS[.m...]]]}|{HH[MM[SS[.m...]]]}}[Z|z]
+ * now|{[{YYYY-MM-DD|YYYYMMDD}[T|t| ]]{{HH[:MM[:SS[.m...]]]}|{HH[MM[SS[.m...]]]}}[Z|z]}
* @endcode
+ * If the value is "now" it takes the current time.
* Time is local time unless Z is appended, in which case it is
* interpreted as UTC.
* If the year-month-day part is not specified it takes the current