Jandi, welcome! Great to have your question with us. 
The 
Disneyland After Dark events, including 
Disneyland After Dark: Sweethearts' Nite, are after-hours events designed for Guests of 
ALL ages, including infants; however, tickets will only be required for Guests three years of age or older. If you experience this magical event, come prepared for a late night, as the event will be held from 8 p.m. until midnight, with early park entry beginning at 5 p.m.
Unfortunately, tickets for 
Disneyland After Dark: Sweethearts' Nite are now sold out, so I hope you grabbed tickets already. If you did, you're in for a fun night. The event will include dancing, a firework spectacular, and unique food options only available during 
Sweethearts' Nite.
Suppose you could not secure tickets for 
Sweethearts' Nite. In that case, I hope you consider one of the other 
Disneyland After Dark events that still have tickets available as of February 18, including 
Villians Nite and 
Star Wars Nite. 
Best of luck with your Disney vacation planning! Come again if you would like more tips and advice on Disneyland Resort.
Ta-ta,
Lola