400
The grade posting period is Friday, Dec. 16, at 7 a.m. to Thursday, Dec. 22 at 9 p.m.
INSTEAD OF
The grade posting period is Friday, Dec. 16 at 7 a.m. to Thursday, Dec. 22 at 9 p.m.
What is the example given in the AP Stylebook's "months" guidance. It gives a similar punctuation example, setting off the date.