Billing in Units

Hello,
We bill in Units. 1 Hours =4 Units: 1 Unit=15mins.
I Would Like Excel to read the Timesheet and report the Units per day worked. I've Attached my Workbook for you to look over.

Rounding Up or down does come into play

Example 1> 10:36am - 1:02pm (10 units)

10:36 - 11:36 = 1hr = 4 units
11:36 - 12:36 = 1 hr = 8 units
12-36 - 12:51 = 15 mins = 1 unit = 9 units
12:51 - 1:02 = 11 mins = 1 unit (auto round up*over 7 mins) = 10 units

Example 2> 10:36a - 12:57p (9 units)

10:36 - 11:36 = 1hr = 4 units
11:36 - 12:36 = 1 hr = 8 units
12-36 - 12:51 = 15 mins = 1 unit = 9 units
12:51 - 12:57 = 6 mins = 0 units

Example> 5:22 pm-10:45pm = 22 units

5:22p - 10:22p = 5hrs/20units
10:22p - 10:37p =15mins/1unit
10:37p - 10:45p = 8 mins/1 unit