PHP Converting Integer to Date, reverse of strtotime
Solution 1
Yes you can convert it back. You can try:
date("Y-m-d H:i:s", 1388516401);
The logic behind this conversion from date to an integer is explained in strtotime in PHP:
The function expects to be given a string containing an English date format and will try to parse that format into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 UTC), relative to the timestamp given in now, or the current time if now is not supplied.
For example, strtotime("1970-01-01 00:00:00")
gives you 0 and strtotime("1970-01-01 00:00:01")
gives you 1.
This means that if you are printing strtotime("2014-01-01 00:00:01")
which will give you output 1388516401
, so the date 2014-01-01 00:00:01
is 1,388,516,401 seconds after January 1 1970 00:00:00 UTC.
Solution 2
Can you try this,
echo date("Y-m-d H:i:s", 1388516401);
As noted by theGame,
This means that you pass in a string value for the time, and optionally a value for the current time, which is a UNIX timestamp. The value that is returned is an integer which is a UNIX timestamp.
echo strtotime("2014-01-01 00:00:01");
This will return into the value 1388516401, which is the UNIX timestamp for the date 2014-01-01. This can be confirmed using the date() function as like below:
echo date('Y-m-d', 1198148400); // echos 2014-01-01
Solution 3
I guess you are asking why is 1388516401 equal to 2014-01-01...?
There is an historical reason for that. There is a 32-bit integer variable, called time_t
, that keeps the count of the time elapsed since 1970-01-01 00:00:00. Its value expresses time in seconds. This means that in 2014-01-01 00:00:01 time_t
will be equal to 1388516401.
This leads us for sure to another interesting fact... In 2038-01-19 03:14:07 time_t
will reach 2147485547, the maximum value for a 32-bit number. Ever heard about John Titor and the Year 2038 problem? :D
Wasim A.
[email protected] | Skype:wasimxe | Whatsapp: +923455407008
Updated on February 19, 2020Comments
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Wasim A. about 4 years
<?php echo strtotime("2014-01-01 00:00:01")."<hr>"; // output is 1388516401 ?>
I am surprised if it can be reverse. I mean can I
convert 1388516401 to 2014-01-01 00:00:01
. What I actually want to know is, what's the logic behind this conversion. How php convert date to a specific integer.