A format without %d left the day of the month at 0, which mktime and
todate read as the last day of the previous month, and the weekday was
wrong for dates in January and February of 1900 and 2100.
Start parsing from the 1st, so a format without a day now gives the
first of the month, and a time-only format no longer outputs the 8 and
367 placeholders for the weekday and day of the year. This also fixes
the weekday of dates in January and February of 1900 and 2100.
Jay Hemnani
ac35c7dcbb