For consistency, prop=categories&clprop=timestamp now returns timestamps in ISO 8601 format (e.g. 2008-08-23T18:05:46Z) rather than MediaWiki's internal timestamp format (e.g. 20080823180546) as of r40161 [1]. All timestamps that the API outputs are now in ISO 8601 format.
And does it expect input timestamp in this format too ?
for example to make an edit you get the timestamp of the last revision, and set basetimestamp to that. Will this still work ?
Best Regards
Jools