You do it the way it works best for you!
They should be weighed once a week as routine and then switching to weighing every day if you spot any issues . Once a month isn’t enough for you to spot any sudden weight drops issues and be able to act fast enough.
I go out to mine about 7am, top up hay and give a part of their veg portion. If it’s summer, they get put out in their run for the day.
Mid morning i go back out to them and poop pick and remove wet hay every day. Top up hay as necessary
Mid afternoon hay is checked and topped up if necessary
Then in the evening, as mine live in my shed, timing depends on the season but in winter about 4pm they are given the other half of their veg, hay and if it is a pellet day (mine only have pellets a few times a week) then they get their pellets. I go back out at 9pm to give them their heatpads.
If it’s summer, they stay out in their run until 9pm, then get out back in their shed with their hay, other half of veg Portion and pellets (if its a pellet day.)
Full cage clean once a week which is also weigh day and nail clipping/hair cutting when necessary