PHP: Convert negative timestamp to date [closed]

问题:

I have a negative timestamp and I wanted to convert it to a readable date format.

$timestamp = -1861945262080;

If I use date("d-m-Y", $timestamp), it will just output 12-08-2035.

回答1:

The below piece of code transforms your UNIX timestamp to a valid date-month-year. However , passing pretty large negative unix timestamps can produce unexpected results as shown below.

 <?php
    $dt = new DateTime();
    $dt->setTimestamp(-1861945262080); //<--- Pass a UNIX TimeStamp
    echo $dt->format('d-m-Y');

OUTPUT :

12-08-2035

However, you still can pass negative timestamps to the above thing. Consider this excerpt from wikipedia.

The Unix time number is zero at the Unix epoch, and increases by exactly 86400 per day since the epoch. Thus 2004-09-16T00:00:00Z, 12677 days after the epoch, is represented by the Unix time number 12677 × 86400 = 1095292800. This can be extended backwards from the epoch too, using negative numbers; thus 1957-10-04T00:00:00Z, 4472 days before the epoch, is represented by the Unix time number -4472 × 86400 = -386380800.

So let's pass the -386380800 to the above code.

 <?php
    $dt = new DateTime();
    $dt->setTimestamp(-386380800); //<--- Pass a UNIX TimeStamp
    echo $dt->format('d-m-Y');

OUTPUT :

04-10-1957

which is the expected output as per the sources.