regex101: To Identify Valid Date Formats

Pro

Non-Capturing Group(?:<[^>]*>)?

?repeats the group contents below at most once:

<the literal < (60₁₀ / 74₈ / 3C₁₆)

Negated Character Class[^>]*

*matches any number of characters outside the set below:

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Group 1(accessed(?:\s*\:?\s*| on ))

accessedthe literal text accessed (case sensitive)

Non-Capturing Group(?:\s*\:?\s*| on )

1st Alternative\s*\:?\s*

\s*any whitespace character, repeated any number of times

\:?optionally matches the literal : (58₁₀ / 72₈ / 3A₁₆)

\s*any whitespace character, repeated any number of times

2nd Alternative on

on the literal text on (case sensitive)

Group 2((?:[0-2]?[0-9]?|30|31)(?:st|nd|rd|th)?)

Non-Capturing Group(?:[0-2]?[0-9]?|30|31)

1st Alternative[0-2]?[0-9]?

Character Class[0-2]?

?matches at most one character from the set below:

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

Character Class[0-9]?

?matches at most one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

2nd Alternative30

30the literal text 30

3rd Alternative31

31the literal text 31

Non-Capturing Group(?:st|nd|rd|th)?

?repeats the group contents below at most once:

1st Alternativest

stthe literal text st (case sensitive)

2nd Alternativend

ndthe literal text nd (case sensitive)

3rd Alternativerd

rdthe literal text rd (case sensitive)

4th Alternativeth

ththe literal text th (case sensitive)

Non-Capturing Group(?:<\/[^>]*>)?

?repeats the group contents below at most once:

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Negated Character Class[^>]*

*matches any number of characters outside the set below:

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Group 3([\.\-\/ ])

Character Class[\.\-\/ ]

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

1st AlternativeJan(?:uary)?

Janthe literal text Jan (case sensitive)

Non-Capturing Group(?:uary)?

?repeats the group contents below at most once:

uarythe literal text uary (case sensitive)

2nd AlternativeFeb(?:ruary)?

3rd AlternativeMar(?:ch)?

4th AlternativeApr(?:il)?

5th AlternativeMay

6th AlternativeJune?

7th AlternativeJuly?

8th AlternativeAug(?:ust)?

9th AlternativeSep(?:tember)?

10th AlternativeOct(?:ober)?

11th AlternativeNov(?:ember)?

12th AlternativeDec(?:ember)?

13th Alternative[1-9]

14th Alternative1[012]

Group 5([\.\-\/ ])

Non-Capturing Group(?:<[^>]*>)?

Group 6(20\d{2})

Non-Capturing Group(?:<\/[^>]*>)?

Global pattern flags

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

25 tokens

Regular Expression

(?:<[^>]*>)?(accessed(?:\s*\:?\s*| on ))((?:[0-2]?[0-9]?|30|31)(?:st|nd|rd|th)?)(?:<\/[^>]*>)?([\.\-\/ ])(Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|June?|July?|Aug(?:ust)?|Sep(?:tember)?|Oct(?:ober)?|Nov(?:ember)?|Dec(?:ember)?|[1-9]|1[012])([\.\-\/ ])(?:<[^>]*>)?(20\d{2})(?:<\/[^>]*>)?

Unit Tests

There are no unit tests, click to add some.