No, Sometimes they are lock step with 0z and 12z but other times, They are off, And i really haven't paid much attention to at what time frame it happens in.
I have a 4 day total heating system replacement starting Monday at home, So I'll be down with no heat for 2 days, But have made provisions for that part, Temps don't look bad but the snow could be problematic with moving in a new boiler and 2 tanks ...................
I really hope you guys down south cash, Been below avg here but not to the point of your area, I could really do without it, I'm past anything winter now, No use for it other then causing me issues.