The time in La Grande Princesse is the time in ニューヨーク より 1 時間 だけ早いです when ニューヨーク is on standard time, and the same as the time in ニューヨーク when ニューヨーク is on daylight saving time.
La Grande Princesse has not had daylight saving time since 1945.
The IANA time zone identifier for La Grande Princesse is America/St_Thomas.