Unlock the Secret to the Day of the Week Instantly!
Determining the day of the week for significant events like births, weddings, deaths, or any other historical or future date is simple with a little math. Follow these easy steps to calculate the day for any date, whether it's from the past or future, all the way back to the 1700s.
Formula to Find the Day of the Week: (D + M + Y + [Y/4]) mod 7
Here is a simple method to find the day of the week for any given date using just your mind:
D = Date
M = Number corresponding to the month
Y = Last two digits of the year
[Y/4] = Remainder when the last two digits of the year (Y) are divided by 4
Numbers for the Month (Table-1) |
Numbers for the Day of the Week (Table-2) |
|||
|---|---|---|---|---|
| Month | Number | Year < 2000 | Year >= 2000 | |
|
Weekday |
Type-I | Type-II | ||
| January | 1/0* | Saturday | 0 | 1 |
| February | 4/3* | Sunday | 1 | 2 |
| March | 4 | Monday | 2 | 3 |
| April | 0 | Tuesday | 3 | 4 |
| May | 2 | Wednesday | 4 | 5 |
| June | 5 | Thursday | 5 | 6 |
| July | 0 | Friday | 6 | 0 |
| August | 3 | |||
| September | 6 | |||
| October | 1 | |||
| November | 4 | |||
| December | 6 | |||
* For leap years, consider January as 0 and February as 3.
Find the Day of the Week for 30-01-1985
To calculate the day of the week, use the formula: Day = (D + M + Y + (Y/4)) mod 7
- D = Date (30)
- M = Number corresponding to the month (January is 1)
- Y = Last two digits of the year (85 for 1985)
- [Y/4] = The remainder when the last two digits of the year (85) are divided by 4, which is 21
Now, apply the values in the formula:
(30 + 1 + 85 + 21) mod 7 = 137 mod 7
Dividing 137 by 7 gives a remainder of 4.
Therefore, the day is Wednesday.
(Note: Since the birth year is less than 2000, refer to Table-2 under Type-I for this calculation.)
Find the Day of the Week for 01-01-2015
To calculate the day of the week, use the formula: Day = (D + M + Y + (Y/4)) mod 7
- D = Date (1)
- M = Number corresponding to the month (January is 1)
- Y = Last two digits of the year (15 for 2015)
- [Y/4] = The remainder when the last two digits of the year (15) are divided by 4, which is 3 (ignore the remainder)
Now, apply the values in the formula:
(1 + 1 + 15 + 3) mod 7 = 20 mod 7
Dividing 20 by 7 gives a remainder of 6.
Therefore, the day is Thursday.
(Note: Since the year is greater than 2000, refer to Table-2 under Type-II for this calculation.)
Find the Day of the Week for 15-08-1947 (India's Independence Day)
To calculate the day of the week, use the formula: Day = (D + M + Y + (Y/4)) mod 7
- D = Date (15)
- M = Number corresponding to the month (August is 3)
- Y = Last two digits of the year (47 for 1947)
- [Y/4] = The remainder when the last two digits of the year (47) are divided by 4, which is 11 (ignore the remainder)
Now, apply the values in the formula:
(15 + 3 + 47 + 11) mod 7 = 76 mod 7
Dividing 76 by 7 gives a remainder of 6.
Therefore, the day is Friday.
(Note: Since the year is less than 2000, refer to Table-2 under Type-I for this calculation.)
