regex101: yyyy/mm/dd

^start of line

Group 1(((\d{3}[1-9]|\d{2}[1-9]\d|\d[1-9]\d{2}|[1-9]\d{3})(\/)(((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))|((0[469]|11)(\/)(0[1-9]|[12]\d|30))|(02(\/)(0[1-9]|[1]\d|2[0-8]))))|(((\d{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))(\/)02(\/)29))

1st Alternative((\d{3}[1-9]|\d{2}[1-9]\d|\d[1-9]\d{2}|[1-9]\d{3})(\/)(((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))|((0[469]|11)(\/)(0[1-9]|[12]\d|30))|(02(\/)(0[1-9]|[1]\d|2[0-8]))))

Group 2((\d{3}[1-9]|\d{2}[1-9]\d|\d[1-9]\d{2}|[1-9]\d{3})(\/)(((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))|((0[469]|11)(\/)(0[1-9]|[12]\d|30))|(02(\/)(0[1-9]|[1]\d|2[0-8]))))

Group 3(\d{3}[1-9]|\d{2}[1-9]\d|\d[1-9]\d{2}|[1-9]\d{3})

1st Alternative\d{3}[1-9]

\d{3}a digit, repeated exactly 3 times

Character Class[1-9]

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

2nd Alternative\d{2}[1-9]\d

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

Character Class[1-9]

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

\da digit

3rd Alternative\d[1-9]\d{2}

\da digit

Character Class[1-9]

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

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

4th Alternative[1-9]\d{3}

Character Class[1-9]

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

\d{3}a digit, repeated exactly 3 times

Group 4(\/)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 5(((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))|((0[469]|11)(\/)(0[1-9]|[12]\d|30))|(02(\/)(0[1-9]|[1]\d|2[0-8])))

1st Alternative((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))

Group 6((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))

Group 7(0[13578]|1[02])

1st Alternative0[13578]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[13578]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

7the literal 7 (55₁₀ / 67₈ / 37₁₆)

8the literal 8 (56₁₀ / 70₈ / 38₁₆)

2nd Alternative1[02]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[02]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Group 8(\/)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 9(0[1-9]|[12]\d|3[01])

1st Alternative0[1-9]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

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

2nd Alternative[12]\d

3rd Alternative3[01]

2nd Alternative((0[469]|11)(\/)(0[1-9]|[12]\d|30))

3rd Alternative(02(\/)(0[1-9]|[1]\d|2[0-8]))

2nd Alternative(((\d{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))(\/)02(\/)29)

$end of line

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

Search reference

Regular Expression

^(((\d{3}[1-9]|\d{2}[1-9]\d|\d[1-9]\d{2}|[1-9]\d{3})(\/)(((0[13578]|1[02])(\/)(0[1-9]|[12]\d|3[01]))|((0[469]|11)(\/)(0[1-9]|[12]\d|30))|(02(\/)(0[1-9]|[1]\d|2[0-8]))))|(((\d{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))(\/)02(\/)29))$

New

2020/02/29
2021/02/29
2021/08/25

Regular Expressions 101

Regular Expression

Extraction