Here is a set of cards numbered 1-31 that would work well in your pocket chart calendar. In addition to showing each number/date with place value cubes, the cards follow an ABC pattern as well. These cards can also be used in your math centers or math tubs for ordering numbers or reviewing place value.
This is a handy set to have around as it is not theme based and can be used any time of year.
I hope you will find this a helpful additon to your daily calendar time, math centers, or both.