^start of line
Group 1((\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-((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(\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29 Group 2(\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00) 1st Alternative\d\d[2468][048] \da digit
\da digit
2the literal 2 (5010 / 628 / 3216)
4the literal 4 (5210 / 648 / 3416)
6the literal 6 (5410 / 668 / 3616)
8the literal 8 (5610 / 708 / 3816)
0the literal 0 (4810 / 608 / 3016)
4the literal 4 (5210 / 648 / 3416)
8the literal 8 (5610 / 708 / 3816)
2nd Alternative\d\d[13579][26] \da digit
\da digit
1the literal 1 (4910 / 618 / 3116)
3the literal 3 (5110 / 638 / 3316)
5the literal 5 (5310 / 658 / 3516)
7the literal 7 (5510 / 678 / 3716)
9the literal 9 (5710 / 718 / 3916)
2the literal 2 (5010 / 628 / 3216)
6the literal 6 (5410 / 668 / 3616)
\da digit
\da digit
0the literal 0 (4810 / 608 / 3016)
4the literal 4 (5210 / 648 / 3416)
8the literal 8 (5610 / 708 / 3816)
4th Alternative[02468][048]00 0the literal 0 (4810 / 608 / 3016)
2the literal 2 (5010 / 628 / 3216)
4the literal 4 (5210 / 648 / 3416)
6the literal 6 (5410 / 668 / 3616)
8the literal 8 (5610 / 708 / 3816)
0the literal 0 (4810 / 608 / 3016)
4the literal 4 (5210 / 648 / 3416)
8the literal 8 (5610 / 708 / 3816)
5th Alternative[13579][26]00 1the literal 1 (4910 / 618 / 3116)
3the literal 3 (5110 / 638 / 3316)
5the literal 5 (5310 / 658 / 3516)
7the literal 7 (5510 / 678 / 3716)
9the literal 9 (5710 / 718 / 3916)
2the literal 2 (5010 / 628 / 3216)
6the literal 6 (5410 / 668 / 3616)
-02-29the literal text -02-29 2nd Alternative\d{4}-((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{4}a digit, repeated exactly 4 times
-the literal - (4510 / 558 / 2D16)
Group 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])) 1st Alternative(0[13578]|1[02])-(0[1-9]|[12]\d|3[01]) 0the literal 0 (4810 / 608 / 3016)
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)
1the literal 1 (4910 / 618 / 3116)
0the literal 0 (4810 / 608 / 3016)
2the literal 2 (5010 / 628 / 3216)
-the literal - (4510 / 558 / 2D16)
Group 5(0[1-9]|[12]\d|3[01]) 2nd Alternative(0[469]|11)-(0[1-9]|[12]\d|30) 3rd Alternative(02)-(0[1-9]|1\d|2[0-8]) Tthe literal T (8410 / 1248 / 5416) (case sensitive)
:the literal : (5810 / 728 / 3A16)
\da digit
:the literal : (5810 / 728 / 3A16)
\da digit
\.the literal . (4610 / 568 / 2E16)
\d{3}a digit, repeated exactly 3 times
Group 11([+-]([01]\d|2[0-3]):[0-5]\d|Z) $end of line
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