PHP Date and Time

Your Two Friends

date()
strtotime()

If you have to do something related to date and time these 2 functions are your friends. Now let’s see how they work.

strtotime()

This function gets a string as argument. The argument can be:

25 aug 2021
25 august 2021
aug 25 2021
2020-08-25
08/25/2021

or even a more descriptive text like:

7 days ago
7 years ago
7 years 2 months 24 days ago

This function returns a timestamp

What is a timestamp? It’s a number

It’s the number of seconds from 1st of january 1970.

That timestamp can be formatted to a date later or can be used to do calculations.

Let’s see some examples:

echo strtotime("today");                       
// 1637362800

echo strtotime("yesterday");                   
// 1637276400

echo strtotime("tomorrow");                    
// 1637449200

echo strtotime("last week");                   
// 1636351447

echo strtotime("last month");                  
// 1634706247

echo strtotime("next tuesday");                
// 1637622000

echo strtotime("3 days ago");                  
// 1637129047

echo strtotime("2 months ago");                
// 1632114247

echo strtotime("2 year 2 months 2 days ago");  
// 1568783047

echo strtotime("+3 weeks");                    
// 1639202647

echo strtotime("-3 weeks");                    
// 1635570247

echo strtotime("27 aug 2022");                 
// 1661551200

echo strtotime("27 august 2022");              
// 1661551200

echo strtotime("aug 27 2022");                 
// 1661551200

echo strtotime("2022-08-27");                  
// 1661551200

echo strtotime("08/27/2022");                  
// 1661551200

date()

For the first argument it gets the formatting of the date.

For example 'Y-m-d' is the standard ISO format for dates 2021-11-14

The second argument is a timestamp. If you don’t specify it, you'll get the current date and time with the formatting you want.

For example

date('Y-m-d') will give me today which is 2021-11-22 But if you specify a date like date('Y-m-d',strtotime('2 days ago')); you will get 2021-11-20

date('Y-m-d');
// today (2021-11-22)

date('Y-m-d',strtotime('2 days ago'));
// 2021-11-20

Let’s change the formatting of those timestamps we saw in strtotime() and see their outputs

<?php
echo date('Y-m-d',strtotime("today"));                       
// 1637362800 -> 2021-11-20

echo date('Y-m-d',strtotime("yesterday"));                   
// 1637276400 -> 2021-11-19

echo date('Y-m-d',strtotime("tomorrow"));                    
// 1637449200 -> 2021-11-21

echo date('Y-m-d',strtotime("last week"));                   
// 1636351447 -> 2021-11-08

echo date('Y-m-d',strtotime("last month"));                  
// 1634706247 -> 2021-10-20

echo date('Y-m-d',strtotime("next tuesday"));                
// 1637622000 -> 2021-11-23

echo date('Y-m-d',strtotime("3 days ago"));                  
// 1637129047 -> 2021-11-17

echo date('Y-m-d',strtotime("2 months ago"));                
// 1632114247 -> 2021-09-20

echo date('Y-m-d',strtotime("2 year 2 months 2 days ago"));  
// 1568783047 -> 2019-09-18

echo date('Y-m-d',strtotime("+3 weeks"));                    
// 1639202647 -> 2021-12-11

echo date('Y-m-d',strtotime("-3 weeks"));                    
// 1635570247 -> 2021-10-30

echo date('Y-m-d',strtotime("27 aug 2022"));                 
// 1661551200 -> 2022-08-27

echo date('Y-m-d',strtotime("27 august 2022"));              
// 1661551200 -> 2022-08-27

echo date('Y-m-d',strtotime("aug 27 2022"));                 
// 1661551200 -> 2022-08-27

echo date('Y-m-d',strtotime("2022-08-27"));                  
// 1661551200 -> 2022-08-27

echo date('Y-m-d',strtotime("08/27/2022"));                  
// 1661551200 -> 2022-08-27

Date Formats

here is a list of formats you can have as the first argument.

<?php
// today is 2021-11-20 at 10:15:50

// The day of the month (from 01 to 31)
echo date('d'); // 20

// The day of the month (three letters)
echo date('D'); // Sat

// The day of the month without leading zeros (1 to 31)
echo date('j'); // 20

// (lowercase 'L') The day of the month full text
echo date('l'); // Saturday

// The ISO-8601 numeric representation of a day (1 for Monday, 7 for Sunday)
echo date('N'); // 6

// The English ordinal suffix for the day of the month (2 characters st, nd, rd or th. Works well with j)
echo date('S'); // th

// A numeric representation of the day (0 for Sunday, 6 for Saturday)
echo date('w'); // 6

// The day of the year (from 0 through 365)
echo date('z'); // 323

// The ISO-8601 week number of year (weeks starting on Monday)
echo date('W'); // 46

// A full textual representation of a month (January through December)
echo date('F'); // November

// A numeric representation of a month (from 01 to 12)
echo date('m'); // 11

// A short textual representation of a month (three letters)
echo date('M'); // Nov

// A numeric representation of a month, without leading zeros (1 to 12)
echo date('n'); // 11

// The number of days in the given month
echo date('t'); // 30

// Whether it's a leap year (1 if it is a leap year, 0 otherwise)
echo date('L'); // 0

// The ISO-8601 year number
echo date('o'); // 2021

// A four digit representation of a year
echo date('Y'); // 2021

// A two digit representation of a year
echo date('y'); // 21

// Lowercase am or pm
echo date('a'); // am

// Uppercase AM or PM
echo date('A'); // AM

// Swatch Internet time (000 to 999)
echo date('B'); // 427

// 12-hour format of an hour (1 to 12)
echo date('g'); // 10

// 24-hour format of an hour (0 to 23)
echo date('G'); // 10

// 12-hour format of an hour (01 to 12)
echo date('h'); // 10

// 24-hour format of an hour (00 to 23)
echo date('H'); // 10

// Minutes with leading zeros (00 to 59)
echo date('i'); // 15

// Seconds, with leading zeros (00 to 59)
echo date('s'); // 50

// The timezone identifier (Examples: UTC, GMT, Atlantic/Azores)
echo date('e'); // Europe/Berlin

// (capital i) Whether the date is in daylights savings time (1 if Daylight Savings Time, 0 otherwise)
echo date('I'); // 0

// Difference to Greenwich time (GMT) in hours (Example: +0100)
echo date('O'); // +0100

// Difference to Greenwich time (GMT) in hours:minutes (added in PHP 5.1.3)
echo date('P'); // +01:00

// Timezone abbreviations (Examples: EST, MDT)
echo date('T'); // CET

// Timezone offset in seconds. The offset for timezones west of UTC is negative (-43200 to 50400)
echo date('Z'); // 3600

// The ISO-8601 date (e.g. 2013-05-05T16:34:42+00:00)
echo date('c'); // 2021-11-20T10:15:50+01:00

// The RFC 2822 formatted date (e.g. Fri, 12 Apr 2013 12:01:05 +0200)
echo date('r'); // Sat, 20 Nov 2021 10:15:50 +0100

// The seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)
echo date('U'); // 1637399750

https://youtu.be/-jkzOI_VXLI

Conclusion

Now you know about date and times in PHP.

I recommend you to open a PHP file and write dates in different formats.

If you have any suggestions, questions, or opinions, please contact me. I’m looking forward to hearing from you!

Key takeaways

• working with dates
• working with times
• formating dates