Weekends are where sleep timing slips. The fix is to keep roughly the same window on Saturday and Sunday.
You do not need the exact minute. A window of about an hour around your usual times is enough to count.
The wake time matters most, since you set it with an alarm. Keep weekend wake-up close to the weekday one.
A late weekend night and a long lie-in shift the whole schedule. Monday then feels like starting over, because in a sense it is.
Hold the window and Monday arrives as just another day. There is no reset to recover from, no fog to push through.
If a late night happens, return to the window the next morning rather than chasing the lost sleep all weekend.
Persistent trouble sleeping, even with steady hours, is worth raising with a qualified healthcare professional.