Lịch Vòng Xoay Vĩnh Cửu Rút Gọn

Simplified Perpetual Ring Calendar made to simplify the standard calendar

Changes are:

• Remove days of the week

• Month letters rather than 3 letter abbreviations to make printing easier - Apr = A

Print of a tester piece first to check fitment.

Some fuzzy skin on the outside ring surface helps use.

Colour change at 10.2 on Ring calendar file