Finding the Current Date and Time (PHP Cookbook)

3.2.3. Discussion

The functions strftime( ) and date( ) can produce a variety of formatted time and date strings. They are discussed in more detail in Recipe 3.5. Both localtime( ) and getdate( ), on the other hand, return arrays whose elements are the different pieces of the specified date and time.

The associative array getdate( ) returns has the key/value pairs listed in Table 3-1.

Table 3-1. Return array from getdate( )

Key	Value
`seconds`	Seconds
`minutes`	Minutes
`hours`	Hours
`mday`	Day of the month
`wday`	Day of the week, numeric (Sunday is 0, Saturday is 6)
`mon`	Month, numeric
`year`	Year, numeric
`yday`	Day of the year, numeric (e.g., 299)
`weekday`	Day of the week, textual, full (e.g., "Friday")
`month`	Month, textual, full (e.g., "January")

For example, here's how to use getdate( ) to print out the month, day, and year:

$a = getdate( );
printf('%s %d, %d',$a['month'],$a['mday'],$a['year']);
August 7, 2002

Pass getdate( ) an epoch timestamp as an argument to make the returned array the appropriate values for local time at that timestamp. For example, the month, day, and year at epoch timestamp 163727100 is:

$a = getdate(163727100);
printf('%s %d, %d',$a['month'],$a['mday'],$a['year']);
March 10, 1975

The function localtime( ) returns an array of time and date parts. It also takes an epoch timestamp as an optional first argument, as well as a boolean as an optional second argument. If that second argument is true, localtime( ) returns an associative array instead of a numerically indexed array. The keys of that array are the same as the members of the tm_struct structure that the C function localtime( ) returns, as shown in Table 3-2.

Table 3-2. Return array from localtime( )

Numeric position	Key	Value
`0`	`tm_sec`	Second
`1`	`tm_min`	Minutes
`2`	`tm_hour`	Hour
`3`	`tm_mday`	Day of the month
`4`	`tm_mon`	Month of the year (January is 0)
`5`	`tm_year`	Years since 1900
`6`	`tm_wday`	Day of the week
`7`	`tm_yday`	Day of the year
`8`	`tm_isdst`	Is daylight saving time in effect?

For example, here's how to use localtime( ) to print out today's date in month/day/year format:

$a = localtime( );
$a[4] += 1;
$a[5] += 1900;
print "$a[4]/$a[3]/$a[5]";
8/7/2002

The month is incremented by 1 before printing since localtime( ) starts counting months with 0 for January, but we want to display 1 if the current month is January. Similarly, the year is incremented by 1900 because localtime( ) starts counting years with 0 for 1900.

Like getdate( ), localtime( ) accepts an epoch timestamp as an optional first argument to produce time parts for that timestamp:

$a = localtime(163727100);
$a[4] += 1;
$a[5] += 1900;
print "$a[4]/$a[3]/$a[5]";
3/10/1975

Table 3-1. Return array from getdate( )

Table 3-2. Return array from localtime( )

3.2. Finding the Current Date and Time

3.2.1. Problem

3.2.2. Solution

3.2.3. Discussion

3.2.4. See Also