BTW, if you're wondering why it's happening it's due to how excel stores times internally. It stores time as a fraction of one, so 6am is stored as .25 (1/4 of 24hours) and 6pm is stored as .75 (3/4 of 24hours)
When you enter 16.30 the initial 16 is ignored as you've only formatted the cell for time (if you used a date format it would count it as 16days) and the .30 is interoperated as 7:12 which is 3/10 of 24
Wow Chuck don't they make it complicated, it makes one wonder why they have all those different number formats, when one can just type them out, just as you so kindly suggested.