In PHP to calculate the difference in two dates we have to use mktime function and then find out the difference in seconds. Then this difference in seconds is to be converted in to required month, days or year differences. We will try to learn a general way of identification and then format it accordingly.

We will take the two dates with hour, minutes and seconds. If the hour minute and second is not important then we can keep the values as 0. Once both the time stamps are calculated then the difference in seconds are fund out by subtracting the two. For other differences we have to divide the difference in second in different values and taking the floor math value of it. To get the difference in minutes we have to divide by 60
To get the difference in hours we have to divide by 3600 ( 60 minute x 60 seconds )
To get the difference tin days we have to divide by 86400 ( 24 x 60 x 60 )
To get the difference in months we have to divide by 2628000


Here is the code to do that.

PHP Date Time Validating Date: Checking if date exist PHP Date Today PHP yesterday and previous 7 days from today PHP Date Format Time stamp generator Date selection drop down list box mktime function to generate time stamp Difference in Two dates by using mktime function Finding month, weekday, day of the year etc for any date value Breaking the date string to get month date and year using array