I agree - Excel is a good tool for that kind of thing. There are a couple of useful things I found:
- use Date or Time formatting on cells as appropriate. If in doubt, set the formatting you want manually, don't assume Excel knows what you mean.
- one key to using dates and times in Excel is to remember that, in its internal numbering system, 1 = a day. So, an hour = 1/24 and a second = 1/24/3600 or 1/86400. e.g. =NOW()+6/24 means six hours from now.
- if you type in e.g. 12:34 it assumes that's hh:mm (hours:minutes). If you mean mm:ss (minutes:seconds), enter 12:34.0