Correct, you do not have to claim all of the donations you made in the year on your current year return. It may be more beneficial to carry them forward and claim them on your return for any of the next five years, (or over the next ten years for a gift of ecologically sensitive land made after February 10, 2014).

Here's a link to the CRA information regarding Donations: https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...