YouTube allows you to supplement your videos with host of useful information. For example, if you'd like to display the date a particular video was recorded, you can use YouTube's Video Manager to add a timestamp to the video.
Display Timestamp on YouTube Video
Sign in to YouTube channel. Click on the Profile icon > Creator Studio > Video Manager. Select the video you'd like to stamp followed by the Edit button. Go to Info and Settings > Advanced settings:
Click into the Recording date field to display a calendar widget and select a date: