3.5. Printing a Date or Time in a Specified Format
Use date( ) or strftime( ):
print strftime('%c'); print date('m/d/Y'); Tue Jul 30 11:31:08 2002 07/30/2002
Both date( ) and strftime( ) are flexible functions that can produce a formatted time string with a variety of components. The formatting characters for these functions are listed in Table 3-3. The Windows column indicates whether the formatting character is supported by strftime( ) on Windows systems.
Table 3-3. strftime( ) and date( ) format characters
 The range for seconds extends to 61 to account for leap seconds.
The first argument to each function is a format string, and the second argument is an epoch timestamp. If you leave out the second argument, both functions default to the current date and time. While date( ) and strftime( ) operate over local time, they each have UTC-centric counterparts (gmdate( ) and gmstrftime( )).
The formatting characters for date( ) are PHP-specific, but strftime( ) uses the C-library strftime( ) function. This may make strftime( ) more understandable to someone coming to PHP from another language, but it also makes its behavior slightly different on various platforms. Windows doesn't support as many strftime( ) formatting commands as most Unix-based systems. Also, strftime( ) expects its formatting characters to each be preceded by a % (think printf( )), so it's easier to produce strings with lots of interpolated time and date values in them.
For example, at 12:49 P.M. on July 15, 2002, the code to print out:
It's after 12 pm on July 15, 2002
with strftime( ) looks like:
print strftime("It's after %I %P on %B %d, %Y");
With date( ) it looks like:
print "It's after ".date('h a').' on '.date('F d, Y');
Non-date-related characters in a format string are fine for strftime( ), because it looks for the % character to decide where to interpolate the appropriate time information. However, date( ) doesn't have such a delimiter, so about the only extras you can tuck into the formatting string are spaces and punctuation. If you pass strftime( )'s formatting string to date( ):
print date("It's after %I %P on %B%d, %Y");
you'd almost certainly not want what you'd get:
131'44 pmf31eMon, 15 Jul 2002 12:49:44 -0400 %1 %P o7 %742%15, %2002
To generate time parts with date( ) that are easy to interpolate, group all time and date parts from date( ) into one string, separating the different components with a delimiter that date( ) won't translate into anything and that isn't itself part of one of your substrings. Then, using explode( ) with that delimiter character, put each piece of the return value from date( ) in an array, which is easily interpolated in your output string:
$ar = explode(':',date("h a:F d, Y")); print "It's after $ar on $ar";
3.5.4. See Also
Documentation on date( ) at http://www.php.net/date and strftime( ) at http://www.php.net/strftime; on Unix-based systems, man strftime for your system-specific strftime( ) options; on Windows, see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_crt_strftime.2c_.wcsftime.asp for strftime( ) details.
Copyright © 2003 O'Reilly & Associates. All rights reserved.