How Many Daylight Hours Do People In Different Places On Earth Experience During An Equinox?

I am no expert by any means but I spent 3 weeks in northern Russia (St. Petersburg about 15 years ago.  We were there in June/July.

It was totally daylight for about 21 hours.  It would get dusk from about 3 AM til
6 AM.  I think this was during the equinox.