What is the Days Until Friday Calculator?
This simple tool tells you exactly how many days are left until the next Friday. Whether you are counting down to the weekend, planning a deadline, or just curious, pick today's day of the week and the calculator instantly returns the number of days until Friday — from 0 (it's Friday today) up to 6.
How to use it
Select today's day of the week from the dropdown and the result updates automatically. If you leave it on the current day, the calculator defaults to your device's date. The answer is the count of whole days from today to the upcoming Friday; if today is Friday, the result is 0.
The formula explained
Each day of the week is given an index where Sunday = 1, Monday = 2, ... Saturday = 7, matching standard calendar numbering. Friday is index 6. The number of days until Friday is:
$$\text{Days} = \left(\left(6 - \text{Today}\right) \bmod 7 + 7\right) \bmod 7$$
The two modulo operations handle the "wrap-around" so that days after Friday (Saturday) correctly count forward to next Friday instead of giving a negative number.
Worked example
Suppose today is Monday (\(d = 2\)). Then $$\text{days} = \left(\left(6 - 2\right) \bmod 7 + 7\right) \bmod 7 = (4 + 7) \bmod 7 = 11 \bmod 7 = 4.$$ So there are 4 days until Friday — Tuesday, Wednesday, Thursday, Friday. If today is Saturday (\(d = 7\)): $$\text{days} = \left(\left(6 - 7\right) \bmod 7 + 7\right) \bmod 7 = (-1 + 7) \bmod 7 = 6,$$ meaning Friday is six days away.
FAQ
What does a result of 0 mean? It means today is already Friday.
Does it count today? No — it counts the number of days from today forward until Friday, so today is day zero.
What if today is Saturday? The next Friday is 6 days away, so the result is 6.
