Get a moisture meter and use it ... it will be more reliable than a calendar.

They need to be watered thoroughly, deeply and not very often ... when the soil a few inches from the base is dry several inches down, give it a lot of water very slowly.

Timing will depend on whether it's in a pot, how large a pot, or in the ground.

I love lady slippers too (Pedilanthus macrocarpus) and probably have fifteen of them in my garden in pots and in the ground. I really like them and hope yours does well for you.

I have some in full hot amazing sun, and some in nice bright shade, and lots in-between all combinations are in pots and in ground so they're pretty darn flexible. they like a good drink and then like getting dry, like lazy said. I water them twice a month at this time of year and they seem really happy. How often are you watering yours? Definitely make sure they dry out between big drinks. Good luck and keep us posted! Happy gardening!

Mine are yellowing at the base too. I don't know why. I think I haven't watered in a month but will check if there is a leak somewhere.