How to convert time to timestamp in php

In PHP, time conversion timestamp is a very common operation. Because in many applications, we need to operate time, including formatting time, calculating time difference, judging time sequence, etc. The timestamp is a convenient data format that allows for easy time calculation and comparison. Therefore, knowing how to time convert timestamps in PHP is essential.

In PHP, we can use the built-in function to convert time to timestamp. Here are some common methods.

1. date() function

The date() function can format the time into any form of string, and can also convert the formatted time into a timestamp. . For example, the following code can convert the current time into a timestamp:

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

Among them, the date() function is used to format the current time, 'Y-m-d H:i:s' is the date and time format, strtotime( ) function is used to convert the formatted time into a timestamp.

2. strtotime() function

The strtotime() function can convert a string that conforms to a specific format into a timestamp. For example, the following code can convert the string '2021-08-01 00:00:00' into a timestamp:

$timestamp = strtotime('2021-08-01 00:00:00');

It should be noted that the strtotime() function supports different time formats Different time formats may cause conversion errors.

3. DateTime Class

In PHP5.2 and above, we can use the DateTime class to convert time stamps. This class provides convenient methods for handling time, such as formatting, calculating time differences, etc. The following is a sample code for using the DateTime class for time conversion to a timestamp:

$datetime = new DateTime('2021-08-01 00:00:00');
$timestamp = $datetime->getTimestamp();

Here, we first create a DateTime object, and then call the getTimestamp() method to obtain the timestamp.

It should be noted that the DateTime class uses the system time zone by default. If you need to specify the time zone, you can pass in the second parameter when creating the DateTime object, for example:

$datetime = new DateTime('2021-08-01 00:00:00', new DateTimeZone('Asia/Shanghai'));

The time zone is specified here for 'Asia/Shanghai'.

Summary

The above are three common methods of time conversion timestamps in PHP. Among them, the date() function is suitable for operating on the current time, the strtotime() function is suitable for converting time strings in a specific format, and the DateTime class provides a more convenient time processing method. Different methods need to be selected according to the actual situation to achieve better results.

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