Time Warp is a feature for the players who meet the requirements and have at least one Cookie per second. You can earn the amount of cookies and dark cookies than you can make with only CpS.
1 Day costs 3,000 Rainbow Cookies
7 Days cost 15,000 Rainbow Cookies
14 Days cost 25,000 Rainbow Cookies
This feature is added due to buying cookies for real money is removed. In version 3.8 and latest