PHP时间戳和mysql时间戳的区别

Question

I am really upset with the script I made, in which I did comparison of timestamps. I can see that the timestamps are totally different.

1. For 2012-10-02 03:06:21, timestamp is: 1349190381
2. For 2012-10-02 04:00:50, timestamp is: 1349150450

I can't understand why the second one timestamp is lower than the first, even if the time is bigger. How can I compare two dates?

I am getting these values by strtotime() function.

Clarification : I am using

$current_timestamp = strtotime(date('Y-m-d H:i:s'));

$till_date_timestamp = strtotime($database_object->till_date);

Answer 1

You sure you did it right?

mysql> select from_unixtime(1349190381), from_unixtime(1349150450);
+---------------------------+---------------------------+
| from_unixtime(1349190381) | from_unixtime(1349150450) |
+---------------------------+---------------------------+
| 2012-10-02 09:06:21       | 2012-10-01 22:00:50       |
+---------------------------+---------------------------+
1 row in set (0.00 sec)

php > echo date('r', 1349190381), "\n", date('r', 1349150450);
Tue, 02 Oct 2012 10:06:21 -0500
Mon, 01 Oct 2012 23:00:50 -0500

what string did you use in your strtotime calls? The function CAN mis-interpret inputs and should not be trusted on anything but well-formed and unambiguous date strings.

Answer 2

Don't rely on strtotime ! Also it's obvious that the timezone of PHP is different then the timezone of the database. Make sure the timezones are the same or get current/till timestamp like this (so that they are from one source):

SELECT UNIX_TIMESTAMP() AS 'Current' UNIX_TIMESTAMP(`datefield`) AS 'Till' FROM `table`

Answer 3

this is the result that i got. They differ from what you mentioned in the question.

Code:

    echo strtotime('2012-10-02 03:06:21'); //outputs: 1349147181
    echo "\n";
    echo strtotime('2012-10-02 04:00:50'); //outputs: 1349150450

Edit:

$till_date_timestamp = strtotime($database_object->till_date); make sure that $database_object->till_date is a string.