Taylor Swift Officially Starts Her Wedding Day As She Leaves NYC Apartment

Taylor Swift has officially started her wedding day ... because she just got snapped heading out of her NYC apartment.

It's being reported Taylor arrived at Gigi Hadid's pad ... which is interesting on a lot of levels, if true.

Brides usually start their wedding days with their bridesmaids, so this could be a sign Gigi is in the wedding party ... plus, we know Taylor went to Gigi's earlier this week.

The big day is here, and Taylor's wheels -- literally -- are in motion.

Taylor and Travis Kelce had what is widely believed to be a rehearsal dinner last night at Madison Square Garden ... and they're headed back to the iconic arena later today for their wedding bash.

As we reported ... they've practically turned MSG into Fort Knox with all the security around the place ... and deliveries are still being made as of this morning for that epic bash that's going down there.

It's still unclear if the actual ceremony is going down at MSG -- or another location -- but we know there is going to be a huge shindig at the arena with some of the biggest stars no matter what!