How do I get the earliest possible datetime in php?

问题

My understanding is that datetimes in php are represented as the number of milliseconds after a certain date (some time in 1960 I think?). How to I construct a datetime that represents the earliest allowable date in php? An example possible syntax would be:

$date = new DateTime(0);

but this doesn't work. Is there some other way to do this?

Thanks for any input.

回答1:

You're pretty close

$date = (new DateTime())->setTimestamp(0);

Will give January 1st, 1970

回答2:

echo date('d-m-Y', 0); // outputs: 01-01-1970

epoch 0 gives the unix timestamp 01-01-1970 or 00:00:00 UTC on January 1st 1970.

来源：https://stackoverflow.com/questions/40095859/how-do-i-get-the-earliest-possible-datetime-in-php