# Google Sheets Conditional Formatting Cycle

In Google Sheets I would like to color a cell depending on if the cycle is on or off.

The cycle is for 10 day the cycle is ON then for 5 days the cycle is OFF then repeat.

So if I start the cycle on Jan 1. The cycle would be ON from Jan 1 - Jan 10 then OFF from Jan 11- Jan 16 then ON from Jan 17 - Jan 27 then OFF from Jan 28 - Feb 1 then continue with this pattern for the year or forever.

• Welcome. This is not difficult if done in stages, and research @Rubén has focus. Start by identifying the relevant date, then calculate the day of the year for that date - use the `days` function. For example, March 15, 2020 is the 75th day of the leap year. Now calculate the day in the 15-day cycle - calculated manually, this is day 15; use the `mod` function to express this mathematically - `mod(75,15)` equals 0. Now apply conditional formatting with 3 rules: #1 if mod if between 1 and 10 (the ON Cycle); #2 if mod is between 11 and 14 (the Off cycle); and #3 if mod =0 (also the OFF cycle). Jan 1 '20 at 23:24