Days Since Calculator

To calculate the number of days from a given date, first find the time difference between the 2 dates - start and end date

In Javascript, you can use the inbuilt funtion like getTime()

time diff = Math.abs(endDate.getTime() - startDate.getTime());

Convert the time format to days format

No of Days = timeDiff / (1000 * 3600 * 24);

Compute the Years between two dates

years = Math.floor(number of days / 365);

Months between two dates

months = Math.floor(number of days / 30);

Weeks between two dates

weeks = Math.floor(number of days / 7);

To Calculate Hours, Mins and Seconds between two dates

hours = number of days * 24;

minutes = number of days * 24 * 60;

seconds = number of days * 24 * 60 * 60;

To count days between dates, first get the time in millisecs from both dates

Calculate days between start and end dates using getTime() and convert times to days

millisecondsPerDay = 86400 * 1000;

startDate.setHours(0, 0, 0, 1);

endDate.setHours(23, 59, 59, 999);

time diff = endDate.getTime() - startDate.getTime();

no of days = Math.ceil(time diff / millisecondsPerDay);

Subtract two weekend days for every week in between

weeks = Math.floor(days / 7);

days = days - (weeks * 2);

Remove weekend not previously removed.

if (startDay - endDay > 1)

days = days - 2;

Remove start day if span starts on Sunday(0) but ends before Saturday(6)

if (startDay == 0 && endDay != 6)

days = days - 1

Remove end day if span ends on Saturday(6) but starts after Sunday(0)

if (endDay == 6 && startDay != 0)

days = days - 1