How to convert current time to timestamp in php

In PHP, converting the current time to a timestamp is a relatively simple task. The timestamp is the number of seconds elapsed since the UNIX epoch. UNIX timestamps were originally represented and stored in the IEEE 754 floating-point format, but in 1978, it was converted to a 32-bit integer format. In this article, we will explain how to get the current timestamp in PHP.

First, we need to understand how to get the current time function. In PHP, there is a function date() that can get the current time and format it into the form we need. The syntax of this function is as follows:

date(format,timestamp)

Among them, the format parameter is required and specifies the format of the date/time. Different letters can be used to represent the year, month, day, hour, etc. The timestamp parameter is optional. If not provided, the current system time will be used.

Next, we will introduce how to use the date() function to convert the current time into a timestamp.

Method 1: Use the time() function to get the current timestamp

In PHP, there is a built-in function time(), which returns the value from the UNIX epoch (i.e. 1970 The number of seconds that have elapsed since January 1, 2000 (00:00:00 UTC), which is the timestamp of the current time.

$timestamp = time();
echo $timestamp;

This code block will output the value of the current timestamp. If you need to convert the timestamp to a specific date/time format, you can use the date() function to format it.

Method 2: Use the strtotime() function to convert a date string into a timestamp

strtotime() The function is used to convert common date formats (such as "2019- 01-01", "2022-09-30 12:35:08") to a UNIX timestamp.

$date_str = "2022-09-30 12:35:08";
$timestamp = strtotime($date_str);
echo $timestamp;

The above code block will output the timestamp of the specified date string. It should be noted that the strtotime() function uses the current system time as the base time by default. If the date string does not contain time zone information, the system time zone will be used.

Method 3: Use the DateTime class to convert a datetime object into a timestamp

The DateTime class is a class introduced in PHP 5.2.0 and above, which provides Provides date and time related functions, such as date and time calculation, comparison and formatting.

To convert a datetime object into a timestamp, we can first create a DateTime object and then call its getTimestamp() method.

$date_str = "2022-09-30 12:35:08";
$date_time = new DateTime($date_str);
$timestamp = $date_time->getTimestamp();
echo $timestamp;

The above code block will output the same results as the previous example.

To sum up, there are many ways to convert the current time into a timestamp in PHP, and you can choose the appropriate method according to actual needs. At the same time, you need to pay attention to time zone issues and flexibly apply the date and time functions and classes provided by PHP to handle time-related tasks more conveniently.

The above is the detailed content of How to convert current time to timestamp in php. For more information, please follow other related articles on the PHP Chinese website!