Calendar helps us to see the dates and along with that the week day of that same dates.
Calculating the number of days between two given dates.
Riana stayed at her grandmother's house from 15th July to 12th August. Now long did Riana stay with her grandmother?
Days in July = 31 - 15 = 16 + 1 = 17
Days in August = 12
Total number of days = 17 + 12 = 29
Riana stayed with her grandmother for 29 days.
While calculating days, there are times when we include the first and the last day in calculations. For calculating the number of days of Riana’s stay, we subtract 15 from 31 (since there are 31 days in July) and then add 1 because; we want to include 15th July in our calculation.
What will be the date 26 days after Mach 19.
Days in March = 31 - 19 = 12
Days in April = 26 - 12 = 14
The date 26 days after March 19 will be April 14.
In this example we do not need to include March 19 in the calculation since the date after March 19 is asked for.
What was the date a fortnight before 10th October?
Days in October = 10
Days in September (previous month) = 14 - 10 = 4
30 - 4 = 26
The date a fortnight before 10th October was 26th September.
A fortnight = 14 days.
This calculation is done in three steps.
1. Days in October.
2. Days in the previous month (September in this case).
3. Total days in September — Required number of days of September.
In this example too, the days before October 10 have to be counted. So we do not include October 10 in our calculation.
When counting the number of days before or after a given date, we do not include the given date in' our calculation, but begin counting with the day before or after the given date, as the case may be.