In case this comes in handy for anyone: touchoff is a little perlscript I hacked together last night b/c I couldn’t find anything that would already allow time offseting by default. Perl has sort of lackluster date-handling functions for doing offsets by default (say, compared to PHP); Dave Rolsky has been working on DateTime modules, but honestly, that would’ve been overkill for this thing.
Usage: touchoff +/-TIME FILE... Change the modification times of each FILE by the specified offset. +/-TIME TIME is a decimal number appended by: d, h, m, or s for respective units. Defaults to hours.
todo: try a python version; also, just for fun, a php version