PHP regular expression issue preg_match() on timestamps

Facing issue with regular expression

2013-05-29 15:15:12 string I am matching with /^(d{4})-(d{2})-(d{2})({s}+(d{2}):(d{2}):(d{2}))?$/ with preg_match but not validating … its giving false.

What should be regexp to match 2013-05-29 15:15:12 or 2013-05-29 pattern.

Let’s take a look at your regex first. Between the date and the time you’re matching {s}+. This means “the character {, followed by a space/tab, followed by one or more }‘s“.

Replace {s} with ?:s+ (a non capturing group matching one or more spaces/tabs) so the full regex is

^(d{4})-(d{2})-(d{2})(?:s+(d{2}):(d{2}):(d{2}))?$

DEMO

The {s}+ is wrong. It should be s+. The curly brackets are used as quantifiers or literals only.