Someone can calculate the number of days between the current date and his or her birthday by performing a couple of quick additions. Alternatively, one of the easiest ways to calculate the number of days is to use one of the simple online date calculators available on the Internet.
There are different methods to determining how long to a person's birthday.
Step 1: Current month
Calculate the number of days left in the current month. Subtract the current date from the total days in the month. This is the first number.
Step 2: In-between months
Calculate the number of days in each full month leading up to the month the birthday is in. Do not count the current month or the month the birthday is in. Remember that February has 28 days, April, June, September and November have 30 and the rest have 31. This is the second number.
Step 3: Birth month
Take the day of the birth month; for example, if the birthday is September 14, the number is 14. This is the third number
Step 4: Add it up
Add the three numbers together. This is the total number of days between the current date and the person's birthday.