Hush, Tweeter? Twitter may go down for 2 hours on Friday, Monday

Oprah, Ashton Kutcher and even CNN hosts may have to pause Friday and Monday while Twitter repairs itself.

Friday at 5 pm and Monday, May 11, at 9 am New York time, for an hour each day, Twitter may be putting Tweets on hold.

Twitter is calling it a "significant database upgrade" that will greatly increase system performance," which could stir some anger in Twitterville as Tweets may come to a halt.