Yes! Your requests usage resets at the beginning of each monthly cycle (the date depends on when you created your account or upgraded to a paid plan). The requests always reset at 00:00 UTC on the renewal date.
For instance, if you created a free plan on May 17, your free requests will reset on each 17th of the month. If you upgraded to a paid plan on December 3, the requests of the paid plan will reset on each 3rd of the month.
You can check your next renewal date in the Usage section of your account.