regex101: 0x36210C88C438001A616687456978Aa4d3AdCba35

Pro

^start of line

Non-Capturing Group(?:[\+-]?\d{4}(?!\d{2}\b))

Character Class[\+-]?

?matches at most one character from the set below:

\+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{4}a Unicode decimal digit, repeated exactly 4 times

Negative Lookahead(?!\d{2}\b)

\d{2}a Unicode decimal digit, repeated exactly 2 times

\ba Unicode word boundary

Non-Capturing Group(?:(-?)(?:(?:0[1-9]|1[0-2])(?:\1(?:[12]\d|0[1-9]|3[01]))?|W(?:[0-4]\d|5[0-2])(?:-?[1-7])?|(?:00[1-9]|0[1-9]\d|[12]\d{2}|3(?:[0-5]\d|6[1-6])))(?:[T\s](?:(?:(?:[01]\d|2[0-3])(?:(:?)[0-5]\d)?|24\:?00)(?:[\.,]\d+(?!:))?)?(?:\2[0-5]\d(?:[\.,]\d+)?)?(?:[zZ]|(?:[\+-])(?:[01]\d|2[0-3]):?(?:[0-5]\d)?)?)?)?

?repeats the group contents below at most once:

Group 1(-?)

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:(?:0[1-9]|1[0-2])(?:\1(?:[12]\d|0[1-9]|3[01]))?|W(?:[0-4]\d|5[0-2])(?:-?[1-7])?|(?:00[1-9]|0[1-9]\d|[12]\d{2}|3(?:[0-5]\d|6[1-6])))

1st Alternative(?:0[1-9]|1[0-2])(?:\1(?:[12]\d|0[1-9]|3[01]))?

Non-Capturing Group(?:0[1-9]|1[0-2])

1st Alternative0[1-9]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

2nd Alternative1[0-2]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-2]

0-2one character from 0 (48₁₀) to 2 (50₁₀)

Non-Capturing Group(?:\1(?:[12]\d|0[1-9]|3[01]))?

?repeats the group contents below at most once:

\1the text saved by group 1

Non-Capturing Group(?:[12]\d|0[1-9]|3[01])

1st Alternative[12]\d

Character Class[12]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

\da Unicode decimal digit

2nd Alternative0[1-9]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

3rd Alternative3[01]

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[01]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2nd AlternativeW(?:[0-4]\d|5[0-2])(?:-?[1-7])?

Wthe literal W (87₁₀ / 127₈ / 57₁₆) (case insensitive)

Non-Capturing Group(?:[0-4]\d|5[0-2])

1st Alternative[0-4]\d

Character Class[0-4]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

\da Unicode decimal digit

2nd Alternative5[0-2]

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

Character Class[0-2]

Non-Capturing Group(?:-?[1-7])?

3rd Alternative(?:00[1-9]|0[1-9]\d|[12]\d{2}|3(?:[0-5]\d|6[1-6]))

Non-Capturing Group(?:[T\s](?:(?:(?:[01]\d|2[0-3])(?:(:?)[0-5]\d)?|24\:?00)(?:[\.,]\d+(?!:))?)?(?:\2[0-5]\d(?:[\.,]\d+)?)?(?:[zZ]|(?:[\+-])(?:[01]\d|2[0-3]):?(?:[0-5]\d)?)?)?

$end of line

Global pattern flags

u modifier: unicode. Treats the pattern and subject as UTF-16

s modifier: single line. Allows a dot to match line terminators

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

U modifier: Ungreedy. Quantifiers are lazy by default. A trailing ? makes a quantifier greedy

J modifier: Allow duplicate subpattern names

25 tokens

Regular Expression

^(?:[\+-]?\d{4}(?!\d{2}\b))(?:(-?)(?:(?:0[1-9]|1[0-2])(?:\1(?:[12]\d|0[1-9]|3[01]))?|W(?:[0-4]\d|5[0-2])(?:-?[1-7])?|(?:00[1-9]|0[1-9]\d|[12]\d{2}|3(?:[0-5]\d|6[1-6])))(?:[T\s](?:(?:(?:[01]\d|2[0-3])(?:(:?)[0-5]\d)?|24\:?00)(?:[\.,]\d+(?!:))?)?(?:\2[0-5]\d(?:[\.,]\d+)?)?(?:[zZ]|(?:[\+-])(?:[01]\d|2[0-3]):?(?:[0-5]\d)?)?)?)?$

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