Hi! Here is a sample of the different versions:

Present, unedited:    Starting the twelve o’clock shifts the chill outside is unreal, especially after such a hot midsummer day. Nonetheless, tonight is going to be a neat break from the usual office routine sitting behind a dull desk all day.
Despite the weird cool weather, it is quiet and peaceful just how Angela wanted it. Patrolling on the outskirts of town, she gets startled when an unusual black murkiness hinders her vision. She gets alarmed as a thick fog appears on the road in front of her and quickly engulfs her car. She looks and checks the time on the dash. It is exactly one o’clock in the morning.

Past, edited: Starting the twelve o’clock shift, the chill outside was unreal, especially after such a hot midsummer day. Nonetheless, tonight was going to be a welcome break from the usual, dull office routine of sitting behind a desk all day.
Despite the weird, cool weather, it was quiet and peaceful, just how Angela wanted it. Routine, but relaxing. Then, patrolling on the outskirts of town, she was startled by an unusual black murkiness that seemed to appear out of nowhere, hindering her vision. She was alarmed when the thick, black fog quickly engulfed her car. Ever the professional, she checked the time on the dash. It was exactly one o’clock in the morning.

This should give you an idea. Just so you know, dialogue remains in the present tense, regardless of which you'd like to go with for the narrative. 

I received your other materials through the sample edit upload. I'll take care of them and add them to the end of the MS.

Let me know which tense you'd like to use--either way I will make it correct and readable.

Thank you!
Laura