How to Convert String to Date and Date-Time in PHP

1. Combination of strtotime() and date
2. Use DateTime::createFromFormat or date_create_from_format

To convert a string to Date and DateTime, several functions or methods can be used, like the combination of strtotime() and date(), using the DateTime::createFromFormat class method or format() method within the same class, or the PHP built-in function of date_create_from_format.

Combination of strtotime() and date

The strtotime() function returns the number of seconds passed from January 01, 1970, just like a Linux machine timestamp. It returns the total seconds from the provided parameter passed to the function.

Parameters:

• Time/Date (required) - This parameter specifies the date/time with string format.
• Now (optional) - This parameter is the timestamp that can be used as a base on the calculation of relative dates

The date() function is the one that formats the local date and time, and return a new formatted date string.

Parameters:

• format (required) - This parameter specifies the format of the provided string.
• timestamp (optional) - This parameter is an integer UNIX timestamp and the default value is the current local time.

To properly use both strtotime() and date(), use strtotime() on the first date and then use date() to convert it back.

Example:

$oldDate = strtotime('03/08/2020');

$newDate = date('Y-m-d',$time);

echo $newDate;
//output: 2020-03-08

Note: There’s a huge difference between / and - when using as a divider on formatting a date, if the separator is a / then the American format m/d/y is assumed; and if the divider is a -, then the European d-m-y format is assumed. To avoid ambiguity, it is recommended to use ISO 8601 (YYYY-MM-DD) dates.

Use DateTime::createFromFormat or date_create_from_format

The DateTime::createFromFormat is a built-in PHP function that returns a new DateTime object that represents the date and time format. On the other hand, date_create_from_format is a procedural style using the DateTime::createFromFormat.

Parameters:

• Format (required) - This parameter specifies what format to use.
• Time (required) - This parameter represents date/time string. If this parameter is NULL, then it will use the current date/time.
• Timezone (optional) - The time zone of time. The default value is the current time zone.

Example of DateTime::createFromFormat

echo $dateNew = DateTime::createFromFormat('m-d-Y', '03-08-2020')->format('Y/m/d');
//output: 2020/03/08

Example of date_create_from_format

echo $dateNew = date_create_from_format("m-d-Y", "03-08-2020")->format("Y-m-d");
//output: 2020/03/08

The only difference between date_create_from_format and DateTime::createFromFormat is that the DateTime::createFromFormat is not available in PHP 5.2 and below.