Counting with datestamps... eg: adding X days to a datestamp

dico

Hello,

How would I do this. I have a datestamp such as 2008-05-28.... I know I want to add 10 days to this, to bring it up to 2008-06-07.

How can I do this? in my head, it looks like:

$new_date = '2008-06-07' + 10;

Whats the best way to do this?

Thanks,

-dr

Weedpacket

[man]strtotime[/man] might be the most straightforward method, depending on where this datestamp is coming from.

dico

Thanks... the strtotime works... however outputs in a timestamp.... can I format it to output as YYYY-MM-DD ? Or will I need to do another step (eg: date('Y-m-d',strtotime(YYYY-MM-DD +3 day)) ?

-dr

Weedpacket

That's what date is for 🙂

Magfersile

Well, in it's simplest form, it might look something like this:

$date = '2008-06-07';
$day_in_seconds = 86400;
$new_date = (strtotime($date) + ($day_in_seconds * 10));

echo date("Y-m-d", $new_date);

which produces the following output:

2008-06-17

The reason for the $day_in_seconds variable is because strtotime() returns the number of seconds since the epoch (the number of seconds since January 1 1970 00:00:00 GMT).

Hope that helps.

Weedpacket

Magfersile wrote:
Well, in it's simplest form, it might look something like this:

Two points about that.

Not all days are 86400 seconds long.
strtotime is a bit smarter than that.

Magfersile

So, if years are 365 1/4 days long (I'm guessing, since there is a leap year every 4 years) you mean that strtotime() takes into account the 1 day per year that is slightly longer?

bradgrafelman

I believe Weedpacket means that you should instead do:

$new_date = strtotime($date . ' +10 days');

and let [man]strtotime/man do the necessary calculation.

Magfersile

Wow. Learn something new everyday. 🙂 Thanks for clearing that up.