Time Processing in php

<?
/**
* Convert to UNIX Timestamp
*/
Function gettime ($ d ){
If (is_numeric ($ d ))
Return $ d;
Else {
If (! Is_string ($ d) return 0;
If (ereg (":", $ d )){
$ Buf = split ("+", $ d );
$ Year = split ("[-/]", $ buf [0]);
$ Hour = split (":", $ buf [1]);
If (eregi ("pm", $ buf [2])
$ Hour [0] + = 12;
Return mktime ($ hour [0], $ hour [1], $ hour [2], $ year [1], $ year [2], $ year [0]);
} Else {
$ Year = split ("[-/]", $ d );
Return mktime (0, 0, 0, $ year [1], $ year [2], $ year [0]);
}
}
}

/**
*
* DateAdd (interval, number, date)
* Returns the date with the specified interval added.
* Inetrval indicates the time interval string expression to be added, for example, minute or day
* Number is a numeric expression that represents the number of time intervals to be added.
* Date indicates the Date.
*
* Interval (Time Interval string expression) can be any of the following values:
* Yyyy year
* Q Quarter
* M Month
* Y Day of year
* D Day
* W Weekday
* Ww Week of year Week
* H Hour
* N Minute points
* S Second seconds
* W, y, and d play the same role, that is, add one day to the current date, add three months to q, and add seven days to ww.
*/
Function DateAdd ($ interval, $ number, $ date ){
$ Date = gettime ($ date );
$ Date_time_array = getdate ($ date );
$ Hours = $ date_time_array ["hours"];
$ Minutes = $ date_time_array ["minutes"];
$ Seconds = $ date_time_array ["seconds"];
$ Month = $ date_time_array ["mon"];
$ Day = $ date_time_array ["mday"];
$ Year = $ date_time_array ["year"];
Switch ($ interval ){
Case "yyyy": $ year + = $ number; break;
Case "q": $ month + = ($ number * 3); break;
Case "m": $ month + = $ number; break;
Case "y ":
Case "d ":
Case "w": $ day + = $ number; break;
Case "ww": $ day + = ($ number * 7); break;
Case "h": $ hours + = $ number; break;
Case "n": $ minutes + = $ number; break;
Case "s": $ seconds + = $ number; break;
}
$ Timestamp = mktime ($ hours, $ minutes, $ seconds, $ month, $ day, $ year );
Return $ timestamp;
}

/**
* DateDiff (interval, date1, date2)
* Returns the interval between two dates.
* Intervals (Time Interval string expression) can be any of the following values:
* W weeks
* D days
* H hour
* N minutes
* S seconds
*/
Function DateDiff ($ interval, $ date1, $ date2 ){
// Obtain the number of seconds between two dates
$ Timedifference = gettime ($ date2)-gettime ($ date1 );
Switch ($ interval ){
Case "w": $ retval = bcdiv ($ timedifference, 604800); break;
Case "d": $ retval = bcdiv ($ timedifference, 86400); break;
Case "h": $ retval = bcdiv ($ timedifference, 3600); break;
Case "n": $ retval = bcdiv ($ timedifference, 60); break;
Case "s": $ retval = $ timedifference; break;
}
Return $ retval;
}

?>



<?
// Test example
$ D1 = "2002-01-11 ";
$ D2 = date ("Y-m-d", dateadd ("d", 15, $ d1 ));

Echo $ d1. ". datediff (" d ", $ d1, $ d2)." The day is $ d2 <br> ";
Echo $ d1. "10 days ago is ". date ("Y-m-d", dateadd ("d",-10, $ d1 )). "<br> ";
$ D3 = date ("Y/m/d H: I: s ");
Echo "now". $ d3. "there are still". datediff ("s", $ d3, "12:59:59"). "seconds <br>" from 12:59:59 ";

?>