Spring equinox occurs today at 19:14HST. Today there will be little difference between the length of the night compared to number of daylight hours. This is the first day of spring as marked by many cultures in the northern hemisphere.
Some calendars may mark the first day of spring on the 20th. And it is, for much of the world. For Hawai’i the equinox occurs on the 19th when you consider the time zone difference.