Charitable Donations made 12/31/2019 from PST (but processed in EST)

I did some online donations on 12/31/2019 from PST. I have time-stamped email confirmations received on 12/31/2019.  However, I didn't realize that some of the organizations are based on the east coast so the tax receipt they sent has 1/1/2020 as the gift date.  How to handle?  Does when I made the donations from my timezone count?