You should call ... Try to talk to someone.
The Zoo Light event is done by a third party. So, it's best if you change your ticket via Ticketmaster.
I'm pretty sure you can't, but I'd call the zoo and ask
I would call the zoo and ask for an exchange or ask for a refund and buy the day you choose to go.
My general admission ticket only covered us from 10 am to 3:00 pm im assuming after that the lights event starts. Sorry I don't know anything regarding that. Good luck !
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