The Symmetry454 Calendar (Sym454) is a proposal for Gregorian calendar reform developed by Dr. Irv Bromberg of the University of Toronto, Canada. It is a perpetual solar calendar that conserves the traditional 7-day week, has symmetrical equal quarters, and starts every month on Monday. (The last 7 days of December, shown in grey, are intercalary days that are appended only to the end of leap years.)