Numerically described periods are not capitalised:
The preferred style is to use numerals rather than text.
Also refer to Time of day.
For time spans, use an unspaced en dash for simple spans and a spaced en dash for complex spans. A space between the the number and the abbreviation (am or pm) should be retained. For example:
When referring to time of day in prose, use either from/to or between/and in place of the en dash. For example:
The lecture will be held from 9am to 10am on Wednesday.
The seminar takes place between 10am and 4pm on Friday.
Authorised by the Associate Director, Service Delivery & Support
21 January, 2014