In project planning when editing a phase, at the bottom of the screen is a 
section for the quick addition of employee time for the phase (below "Phase 
planning add" link).  Using this tool adds minutes, not hours.

For example, if I enter:

Plan employee purves for 3 hours

Then the program will set a new phase planning item:

| Purves, Chris | 00:03 | 00:03 | 00:00 | Edit Delete |

If I enter:

Plan employee purves for 180 hours

then the program will set a new phase as:

| Purves, Chris | 03:00 | 03:00 | 00:00 | Edit Delete |

Not difficult to work around, and still much faster than using the Phase 
planning add link, but when I get up past 13 hours I start needing a calculator.