How to get the first day of the current year?

Question

I need to use PHP DateTime to get the first day of the current year. I\'ve tried:

$year = new DateTime(\'first day of this year\');
var_dump($year);
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Answer 1

Just wanted to record some nuance with the answer by lorem monkey

The suggested method might cause issues with when using time zones.

scenario: consider current system time is 2018-01-01 00:20:00 UTC and system default time zone is set to UTC.

date('Y') will give you 2018

if you are doing something like:

$startDate = new DateTime('first day of january '.date('Y'), new DateTimeZone('America/New_York'));

This will compute to 'first day of january 2018' but you actually needed the first date of your current year in America/New_York, which is still 2017.

Stop dropping the ball man, its not new year yet!

So it is better to just do

$startDate = new DateTime('first day of january', new DateTimeZone('America/New_York'));

And then do the modifications as needed by using the DateTime::modify() function.

Relative date formats are fun.

My scenario: I wanted to get the bounds of this year as in 2018-01-01 00:00:00 to 2018-12-31 23:59:59

This can be achieved in two ways with relative date formats.

one way is to use the DateTime::modify() function on the object.

$startDate = (new DateTime('now', new DateTimeZone("America/New_York")));
$endDate = (new DateTime('now', new DateTimeZone("America/New_York")));

$startDate->modify("january")
    ->modify("first day of this month")
    ->modify("midnight");
    
$endDate->modify("next year")
    ->modify("january")
    ->modify("first day of this month")
    ->modify("midnight")->modify("-1 second");

var_dump([$startDate, $endDate]);

Try out here: https://www.tehplayground.com/Qk3SkcrCDkNJoLK2

Another way to do this is to separate the relative strings with a comma like so:

$startDate = (new DateTime('first day of january', new DateTimeZone("America/New_York")));
$endDate = (new DateTime('next year, first day of january, -1 second', new DateTimeZone("America/New_York")));
var_dump([$startDate, $endDate]);

Try out here: https://www.tehplayground.com/hyCqXLRBlhJbCyks