what time of day do IPv6 privacy addresses usually rotate on Android devices?

Android long ago implemented support for the privacy extensions of IPv6 networking. It was in 4.0 (Ice Cream Sandwich). The RFC for the privacy extensions doesn't specify (or even recommend) a TTL for temporary addresses, but typically they have a lifetime of 24 hours. My question is how is the expiry time chosen? Is it at multiples of 24 hours after the last boot? Or it is tied to the local timezone (and happens overnight)? Or is it at random, with some jitter from a 24-hour schedule? Or something else?