Introduction to the differences between time(), date(), and mktime() in PHP_PHP Tutorial

checkdate: Verify the correctness of the date.
date: Format the server's time.
strftime: Format the server's time locally.
getdate: Get time and date information.
gettimeofday: Get the current time.
gmdate: Get the time difference between the current time and GMT.
easter_date: Calculate Easter date.
easter_days: Calculate the number of days between Easter and March 21st.
mktime: Get UNIX timestamp.
gmmktime: Get the Greenwich Mean Time of the UNIX timestamp.
time: Get the UNIX timestamp of the current time.
microtime: Get the UNIX timestamp value of the current time in millionths of a second.

　checkdate Verify the correctness of the date.

Syntax: int checkdate(int month, int day, int year);
Return value: Integer
Function type: Time and date
Content description If the date is valid, return true, if the date has problem, return false. This function can be used to check whether the date is valid. The valid range is as follows:
year is from 0 to 32767 years
month is from 1 to December
day, which changes with the month and leap year

date Format the server's time.

Syntax: string date(string format, int [timestamp]);
Return value: String
Function type: Time and date
Content description The string of the return value is determined by the configured format . If there is a timestamp value passed in, the timestamp will be formatted and returned; if there is no timestamp value passed in, the time of the current server will be formatted and returned. To convert dates to other language formats, the setlocale() and strftime() functions should be used. The options for string formatting are as follows:
a - "am" or "pm"
A - "AM" or "PM"
d - day, two digits, if less than two digits Then add zeros in front; such as: "01" to "31"
D - day of the week, three English letters; such as: "Fri"
F - month, full English name; such as: "January"
h - hour in 12-hour format; such as: "01" to "12"
H - hour in 24-hour format; such as: "00" to "23"
g - hour in 12-hour format, less than Two digits are not padded with zeros; for example: "1" to 12"
G - hours in the 24-hour system, less than two digits are not padded with zeros; such as: "0" to "23"
i - minutes; such as: "00" to "59"
j - day, two digits, if there are less than two digits, do not add zeros; such as: "1" to "31"
l - day of the week, full English name; such as: "Friday"
m - month, two digits, if there are less than two digits, add zeros in front; For example: "01" to "12"
n - month, two digits, if there are less than two digits, no Fill in zeros; such as: "1" to "12"
M - month, three English letters; such as: "Jan"
s - seconds; such as: "00" to "59"
S - Add an English ordinal number at the end of the word, two English letters; such as: "th", "nd"
t - the number of days in the specified month; such as: "28" to "31"
U - the total number of seconds
w - numeric day of the week, such as: "0" (Sunday) to "6" (Saturday)
Y - year, four digits; such as: "1999"
y - year, two digits; Such as: "99"
z - the day of the year; such as: "0" to "365"
Other characters not listed above will be listed directly

Usage examples,

Example 1:

Example 2:

Reference gmdate() mktime()
strftime Format the server's time locally.
Syntax: string strftime(string format, int [timestamp]);
Return value: String
Function type: Time and date
Content description The string of the return value is determined by the configured format. If there is a timestamp value passed in, the timestamp will be formatted and returned; if there is no timestamp value passed in, the time of the current server will be formatted locally and returned. The month or day of the week name changes depending on the locale configuration setlocale().
The returned string can be in the following format:
%a The abbreviation of the day of the week.
%A The full name of the day of the week.
%b The abbreviation of the month name.
%B The full name of the month.
%c is a string representing the local date and time better.
%d represents the day of the month as a number (range 00 to 31).
%H represents the hour as a 24-hour number (range 00 to 23).
%I represents the hour as a 12-hour number (range 01 to 12).
%j represents the day of the year as a number (range is 001 to 366).
%m Month number (ranging from 1 to 12).
%M minutes.
%p represents local time in 'AM' or 'PM'.
%S seconds.
%U The number represents the week number of the year, with the first week starting from the first Sunday.
%W The number represents the week number of the year, with the first week starting from the first Monday.
%w represents the day of the week as a number (0 is Sunday).
%x Date representation without time.
%X Time representation without date.
%y is a two-digit number representing the year (range from 00 to 99).
%Y is the complete numerical representation of the year, that is, four digits.
%Z time zone or name abbreviation.
%% % characters.

Usage Example

Refer to setlocale() mktime()
getdate to obtain time and date information.
Syntax: array getdate(int timestamp);
Return value: Array
Function type: Time and date
Content description The elements of the returned array include the following items:
"seconds" - seconds
"minutes" - minutes
"hours" - hours
"mday" - the day of the month
"wday" - the day of the week
"mon" - the month number
"year" - year, number
"yday" - the day of the year; such as: "299"
"weekday" - the full name of the day of the week; such as: "Friday"
" month" - the full name of the month; such as: "January"
gettimeofday Get the current time.
Syntax: array gettimeofday(void);
Return value: Array
Function type: Time and date
Content description The elements of the returned array include the following items:
"sec" - seconds
"usec" - one millionth of a second
"minuteswest" - minutes of Greenwich Mean Time
"dsttime" - the destination time zone
gmdate Get the current time difference from GMT.
Syntax: string gmdate(string format, int timestamp);
Return value: String
Function type: Time and date
Content description: This function is similar to the date() function, except that this function Returns the time difference from Greenwich Mean Time (GMT)

Usage Example

If the machine executing this example is in Finland (Finland, GMT +0200), the returned result is:
Jan 01 1998 00:00:00
Dec 31 1997 22:00:00
Reference date() mktime() gmmktime()
easter_date Calculate Easter date.
Syntax: int easter_date(int [year]);
Return value: Integer
Function type: Time date
Content description: Enter a certain year, and the year will be returned in UNIX timestamp format. The Easter date of , if no year is entered, the date of the current year is calculated. Value? Note that the entered year must be between 1970 and 2037 AD, otherwise it cannot be calculated.
Usage Example

The returned result is

Apr-04-1999
Apr-23-2000
Apr-15-2001
easter_days Calculate the number of days between Easter and March 21st.

Syntax: int easter_days(int [year]);
Return value: Integer
Function type: Time and date
Content description Enter a certain year to calculate Easter and March 2nd of that year The number of dates between eleven days. If no year is entered, it will be calculated based on the current year. This function can be used to replace the problem that easter_date() cannot calculate outside the range of 1970-2037.
Usage Example

The returned result is:
14 (4/4)
32 (4/22)
2 (3/23)
Refer to easter_date()
mktime to obtain the UNIX timestamp.
Syntax: int mktime(int hour, int minute, int second, int month, int day, int year);
Return value: Integer
Function type: Time date
Content description: Enter one time, returns a UNIX timestamp long integer.
Usage Example

Reference date() time()

gmmktime Gets the Greenwich Mean Time of the UNIX timestamp.

Syntax: int gmmktime(int hour, int minute, int second, int month, int day, int year);

Return value: Integer

Function type: Time and date
Content description: If you enter a time, a long integer of UNIX Greenwich time stamp will be returned.
time Get the UNIX timestamp of the current time.
Syntax: int time(void);
Return value: Integer
Function type: Time and date
Content description Return the stamp value of the current time.

Reference date()

microtime Gets the millionth of a second value of the UNIX timestamp of the current time.
Syntax: string microtime(void);
Return value: String
Function type: Time and date
Content description Returns the millionth of a second stamp value of the current time. If the operating system does not provide the system call function of gettimeofday(), this function will also be invalid.