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Unit 8: Working with Strings, Date and Time

It’s best not to touch the $is_dst parameter, because PHP usually interprets the date and time Notes
correctly.
If we replace all calls to mktime() by gmmktime(), the parameters passed to the function are
treated as GMT time, with no time zones taken into account. With mktime(), the time zone that
the server has configured is taken into account. For instance, if you are on Central European
Time (CET), passing the same parameters as shown previously to gmmktime output times that
are one hour “later.” Because the date function does take into account time zones, the generated
GMT timestamp is treated as a CET time zone, resulting in times that are one hour for non DST
times and two hours for DST times (CEST is CET+1).

8.3 Formatting Date and Time

Making a GMT date with gmmktime() and then showing it in the current time zone with the
date() function doesn’t make much sense. Thus, we also have two functions for formatting date/
time: date() to format a local date/time, and gmdate() to format a GMT date/time. Both functions
accept exactly the same parameters. The first parameter is a format string (more about that in a
bit), and the second is an optional timestamp. If the timestamp parameter is not included, the
current time is used in formatting the output. gmdate() and date() always format the date in
English, not in the current “locale” that is set on your system. Two functions are provided to
format local time/date according to locale settings: strftime() for local time and gmstrftime() for
GMT times. Table describes formatting string characters for both functions. Note that the (gm)
strftime() prefix to the formatting string options with a %.

Table 2: Date Formatting Modifiers

Description Date/ Strftime/ Remarks
gmdate gmstrime
AM/PM A
am/pm a %p Either am or pm for the English
locale. Other Locates Migh have
replacements (for example, n1_
NL has an empty atring here).
Century, numeric %C Returne the century number 20
two digits for 2004, and so on.
Character, literal% %% Use this to place a literal character
% inside the formatting string.
Character, newline %n Use this to place a newline
character inside the formatting
string.
Character, tab %t Use this to place a tab character
inside the formatting string.
Day connt in t Number of days in the month
month defined by the timestamp.
Day of month, %e Current day in this month defined
leading spaces by the timestamp. A space is
prepended when the day number
is less than 10.
Contd...

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