Why does it say 24 hours left on Tinder?

As a Tinder Gold or Platinum member, your daily Picks will refresh every 24 hours. If you purchased additional Picks, you have 24 hours to view or swipe them before they disappear.

Why do I have to wait 12 hours on Tinder?

Tinder doesnt let you swipe and swipe forever. They put a cap on how many Likes you can give in a 12-hour period. When Tinder first started doing this, you had 120 Likes per 12 hours. Then they decreased it to 100.