symfony/symfony — pull request #8198 by bamarni (2013-06-04 19:04:15+00:00)
Title: [Form] fixed date type format pattern regex

| Q | A
| ------------- | ---
| Bug fix? | [yes]
| New feature? | [no]
| BC breaks? | [no]
| Deprecations? | [no]
| Tests pass? | [yes]
| License | MIT

I don't understand what is the rationale behind the current regex, why is there mandatory in-between characters?

This regex passes with the format option set to ```dMyyyy``` while it doesn't with ```dMy```, on the linked icu documentation it is stated that ```y``` is equivalent to ```yyyy```.