To date/time stamp a video you need to enable Date/Time stamp.

To do so:
1. On the Tools menu click Options.
2. Under the General tab, select the option "Add a Stamp on Video Recordings and Snaps".
3. Select the "Date and Time" or "Text" stamp.
4. Click OK.

You can also sort the snaps and video by date and time under the Recordings tab at the bottom of the main application interface.