If you've got a Pro subscription, among other nifty features, you can remove the dates from your mashed videos, among other nifty features.
On the iOS app
Tap on the "Date/Caption" button on the mashing screen. Tap on it once again to bring the dates back.
On the Android app
Tap on the "Date Stamp" button on the mashing screen. Tap on it once again to bring the dates back.
