Instead of setting an alarm for different times, set your alarm
clock for the same time every single day. Whether you are on a holiday or day off,
if it’s the weekend or if you’re needed at work, pick a time that will be most
suitable for all instances.

 My chosen time is 7am every day as with this time I
have enough time to get to work, it’s not excessively early.  On days where I’m not needed at work till
11am I can still wake up, this time walk across the room and set the alarm for
another hour if needed. Just gets in the habit of waking up at that time even
if it isn’t needed.

Days off waking up at 7am I have more time in the day to do
things and if I go to sleep around 11pm I still have a full 8 hours sleep.

The same time everyday setting the alarm is growing the habit
and I know that I will be awake at that time so I cannot need to plan too far
in advance as I have enough time when I get up at 7am.