The Time () and Date () Functions:
The time () and date () functions are the two most basic functions we use when working with dates in PHP. The time () function assigns each date and time a number string based in seconds. The date () function then formats it to be human friendly.
The Mktime () Function:
The mktime () function is used to artificially generate the timestamp for an inputed date and time. This works the same as the time () function, except it is for a specified date, and not necessarily today's date.
The Cal_days_in_month () Function:
The cal_days_in_month () function tells you how many days are in a given month of a given year, for a specified calendar. This will come in handy in Februarys if you're not sure if it's leap year!
The Easter_date () Function:
Easter changes date every year, but this function helps determine when it is. This is helpful if you are dynamically adding holidays to your PHP calendar.
One simple script that deals with time is a countdown script. This script counts the days, minutes, or even seconds until and event occurs. It is a great way lead up to a special event.
Another thing we can do is add time. A good example of this is our pregnancy due date calculator where we add the baby's estimated gestation onto the last menstrual date to produce an estimated due date.
A simple calendar:
Using many of the skills mentioned on this page we are able to create a simple calendar in PHP. The calendar determines the number of days in the month, and the correct day of the week each falls on, to create a traditionally formatted calendar.