Regex Editor & Tester

This regular expression matches two different formats for time representation. It matches a string starting with "posix" followed by an optional sequence of digits, typically used for POSIX timestamps (e.g., "posix1610000000"). Alternatively, it matches a partial ISO 8601-like date and time string, where the date is formatted as two-digit pairs separated by any character, followed by an optional four-digit year, the letter 'T', and an optional time component (e.g., "12.31.2021T12:30"). It is useful for validating or extracting loosely structured datetime values.