I live 51.7N -0.2W and the winter solstice day length is 07h 47m. However, the summer solstice night is only 07h 19m. Is this difference all due to the way sunrise and sunset are measured - or are there other factors at play?
Where we are in our orbit makes the difference. We are closest to the Sun in winter (north hemisphere), so daylight will last a little longer. Being closer has at least two effects - the Sun appears slightly larger so it comes up a little earlier and sets a little later. Also, we are moving faster in our orbit, during winter, which adds a little bit more time to daylight. I think this is right, but it’s been a while since I looked closely at this.
IIRC, the longest day or night isn’t the actual solstice day for those reasons.