[przemoc]

If you're *nix user, you can quite easily perform this kind of stuff using date, or at least using date from coreutils.

    $ date -d 'today + 6 weeks'
    Mon Aug 24 13:15:54 CEST 2015
    
    $ TZ=America/New_York date -d 'now + 2 hours'
    Mon Jul 13 09:16:17 EDT 2015

[strictfp]

I had no idea. Great tip, thanks!