Use figures for all dates.
- Frank's party was on Dec. 5, 2007.
*Note - at times ordinals (e.g. 15th) are appropriate when you've expressly noted which year you are discussing.
- Later this year, on Nov. 5th, Paquette will hold his seminar on reconstructive surgery.
Spell out numbers unless referring to a specific time; always use figures with specific a.m. and p.m. times.
- Our meeting lasted until after five.
- The program begins at 8:30 a.m.