Page 513 - Beginning PHP 5.3

Chapter 16: PHP and the Outside World

Date/Time String Meaning
tomorrow 1:30pm The day after the current date at 1:30 pm
Today Midnight on the current date

Yesterday Midnight on the day before the current date
last Thursday Midnight on the Thursday before the current date

+2 days The day after tomorrow at the current time of day
- 1 year One year ago at the current time of day
+3 weeks 4 days 2 hours 3 weeks, 4 days, and 2 hours from now

3 days 3 days after the current date at the current time
4 days ago 4 days before the current date at the current time
3 hours 15 minutes The current time plus 3 hours 15 minutes

As with mktime() , strtotime() assumes by default that the string you pass it represents a date and
time in the computer ’ s time zone, and converts to UTC accordingly. However, you can specify a time in
a different time zone by adding an offset from UTC, using a plus or minus sign followed by a four - digit
number at the end of the string. The first two digits represent the hours component of the offset, and the
second two digits represent the minutes. For example:
$t = strtotime( “February 15th 2004, 9:30am +0000” ); // GMT
$t = strtotime( “February 15th 2004, 9:30am +0100” ); // 1 hour ahead of GMT
$t = strtotime( “February 15th 2004, 9:30am -0500” ); // Indianapolis time
$t = strtotime( “February 15th 2004, 9:30am +1000” ); // Sydney time (not DST)

$t = strtotime( “February 15th 2004, 9:30am +1100” ); // Sydney time (with DST)
strtotime() calculates relative dates (such as “ tomorrow 1:30pm ” ) based on the current date. If you
want to calculate a relative date based on a different date, pass that date as a second argument to
strtotime() , in timestamp format:

$localTime = strtotime( “tomorrow 1:30pm”, 0 ); // January 2nd 1970, 1:30:00 pm
Extracting Date and Time Values from a Timestamp
Now you know how to create timestamps from time/date values and strings. You can also go the other
way, and convert a timestamp to its corresponding date and time components.

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