How many minutes in a half an hour?
Chanuka candles need to burn for half an hour after nightfall.
The שר התורה Harav Chaim Kanyevski שליט"א, holds that the half
hour is measured in שעות זמניות of the night time.
In North America in Mid December, a daytime hour* = approximately
45 minutes and a nighttime hour = approximately 75 minutes.
Therefore, half a nighttime hour = approx 37.5 minutes.