Arrangement of parameters related to date() date function in PHP_PHP tutorial

Add
date_default_timezone_set(PRC) to the front of the page; /*Adjust the time to Beijing time, php5 defaults to Greenwich Mean Time*/
date ()
a: "am" or "pm"
A: "AM" or "PM"
d: Day, two digits, zero if missing; from "01" to "31"
D: Day of the week, 3 English letters, such as: "Fri"
F: month, full English name, such as: "January"
h: hour in 12-hour format, from "01" to "12"
H: Hours in 24-hour format, from "00" to "23"
g: Hours in 12-hour format, no zeros added; from "1" to "12"
G: Hours in 24-hour format, no zeros added Zero; from "0" to "23"
j: a few days, not zero if missing; from "1" to "31"
l: day of the week, full English name, such as: "Friday"
m: month, two digits, from "01" to "12"
n: month, two digits, no zero padding; from "1" to "12"
M: month, 3 English digits Letters; such as: "Jan"
s: seconds; from "00" to "59"
S: add an English ordinal number at the end of the word, two English letters, such as: "21th"
t: specify the month Number of days, from "28" to "31"
U: Total seconds
w: Numeric day of the week, from "0 (Sunday)" to "6 (Saturday)"
Y: Year , four digits
y: year, two digits
z: day of the year; from "1" to "366"
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1, year-month-day
indicates the year with uppercase Y and lowercase y;
indicates the month with uppercase F, uppercase M, lowercase m and lowercase n (respectively representing characters and numbers);
can be used to represent the day with lowercase d or lowercase j, and uppercase S represents the suffix of the date.
echo date('Y-m-j');
2007-02-6
echo date('y-n-j');
07-2-6
Capital Y means the fourth day of the year digits, while lowercase y represents the two-digit number of the year;
lowercase m represents the number of the month (with a leading), while lowercase n represents the number of the month without the leading.
echo date('Y-M-j');
2007-Feb-6
echo date('Y-m-d');
2007-02-06
Capital M represents the month 3 abbreviation characters, and lowercase m represents the number of the month (with a leading 0);
There is no uppercase J, only a lowercase j represents the date of the month, without a leading o; if the month needs a leading, use a lowercase d.
echo date('Y-M-j');
2007-Feb-6
echo date('Y-F-jS');
2007-February-6th
Capital M represents the month 3 abbreviation characters, and capital F represents the full English version of the month. (No lowercase f)
Capital S represents the suffix of the date, such as "st", "nd", "rd" and "th", depending on the date number.
2, hours: minutes: seconds
By default, the time displayed by PHP interpretation is "Greenwich Mean Time", which is 8 hours different from our local time.
echo date('g:i:s a');
5:56:57 am
echo date('h:i:s A');
05:56:57 AM
A lowercase g indicates a 12-hour format without leading 0s, while a lowercase h indicates a 12-hour format with leading 0s.
When using the 12-hour clock, you need to indicate morning and afternoon. Lowercase a represents lowercase "am" and "pm", and uppercase A represents uppercase "AM" and "PM".
echo date('G:i:s');
14:02:26
Capital G represents the hour in 24-hour format, but without leading; use capital H to represent with leading 24-hour hour number
Summary:
The letter g represents the hour without a leading, the letter h represents the hour with a leading;
Lowercase g and h represent the 12-hour format, and uppercase G and H represent the 24-hour format.
3, leap year, week, day
echo date('L');
Whether this year is a leap year: 0
echo date('l');
Today is: Tuesday
echo date('D');
Today is: Tue
Capital L indicates whether this year is a leap year, Boolean value, returns 1 if true, otherwise 0;
Lowercase l indicates the day of the week in English Write in full (Tuesday);
and use a capital D to represent the 3-character abbreviation of the day of the week (Tue).
echo date('w');
Today's week: 2
echo date('W');
This week is the 06th week of the year
Lowercase w represents the day of the week , represented in numerical form
Capital W represents the number of weeks in the year
echo date('t');
This month has 28 days
echo date('z');
Today It is the 36th day of this year
Lowercase t indicates the number of days in the current month
Lowercase z indicates the day of the year today
4, others
echo date('T');
UTC
Capital T indicates the time zone setting of the server
echo date('I');
0
Capital I indicates whether it is daylight saving time, and returns 1 if true, otherwise 0
echo date('U');
1170769424
Uppercase U represents the total number of seconds from January 1, 1970 to the present, which is the UNIX timestamp of the Unix time epoch.
echo date('c');
2007-02-06T14:24:43+00:00
Lowercase c represents ISO8601 date, the date format is YYYY-MM-DD, separated by the letter T Date and time, the time format is HH:MM:SS, and the time zone is expressed using the offset from Greenwich Mean Time (GMT).
echo date('r');
Tue, 06 Feb 2007 14:25:52 +0000
Lowercase r represents the RFC822 date.
5. Format time
echo $row["t_time"]; will output 2008-2-29 12:08:00
echo date("Y-m-d",strtotime($row["t_time" ])); will output 2008-2-29
Note, since the time obtained by $row["t_time"] is already a string, you need to use strtotime (string to timestamp) to convert it, otherwise it will output 1970 -01-01 error