[cryptonector]

Adding or subtracting "months" is inherently difficult because months don't have set lengths, varying from 28 through 31 days. Thus adding one month to May 31 is weird: should that be June 30 or July 1 or some other date?

Try not to have to do this sort of thing. You might have to though, and then you'll have to figure out what adding months means for your app.

[mjevans]

Welcome to Business Logic. This is where I'd really like pushback to result in things that aren't edgecases.

However you also run into day to day business issues like:

* What if it's now a Holiday and things are closed?

* What if it's some commonly busy time like winter break? (Not quite a single holiday)

* What if a disaster of somekind (even just a burst waterpipe) halts operations in an unplanned way?

Usually flexability needs to be built in. It can be fine to 'target' +3 months, but specify it as something like +3m(-0d:+2w) (so, add '3 months' ignoring the day of month, clamp dom to a valid value, allow 0 days before or 14 days after),

[TZubiri]

Do all edge cases need to be handled? Just be late when there's a holiday.

72 business hours sounds more like human time than computer time anyways.

[cryptonector]

Yes, basically, they do need to be handled, but you have to define that for your own case. It's a real pain, if you have to do month math.