Does PHP's `time()` Function Return a GMT/UTC Timestamp?

Does PHP time() return a GMT/UTC Timestamp?

The PHP time() function returns a Unix timestamp, which represents the number of seconds that have elapsed since the beginning of the Unix epoch (00:00:00 UTC on January 1, 1970). Therefore, it can be considered as a UTC timestamp.

Unix timestamps are timezone-independent, meaning they represent a specific point in time regardless of the local timezone. This is because they measure the passage of time since the Unix epoch, which is a fixed point in time in UTC.

Converting from a Unix timestamp to a "human readable" time requires specifying the timezone you want it displayed in. For example, the Unix timestamp 1296096875 represents the same point in time in Tokyo (11:54:35), London (02:54:35), and New York (21:54:35) on January 27, 2011.

To handle times effectively, it's important to distinguish between:

• Absolute points in time: These are specific moments in history that can be expressed as Unix timestamps or complete timestamps in any format.
• Local time: Also known as "wall clock time," this refers to the time that is currently being observed in a particular location.
• Incomplete local wall clock time: This is a partial representation of local time that lacks information about the timezone, making it ambiguous.

Understanding these concepts allows you to work effectively with time-related data, whether it's in Unix timestamp or human-readable formats.

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