Validating date using a locale

Hi!

Is there a way to validated a date using a locale? Something like dayjs('15/10/2018', {locale: 'pt-br'}).isValid()?

Thank you!

[prantlf]

Yes, the #340 parses using only the specified format. It does not pass the input to the Date constructor as a fallback. For example:

dayjs('15/10/2018', { format: 'DD/MM/YYYY' }).isValid()

You see, that you do not need to provide the locale, but you need to know the Portuguese official date format. If you wanted to specify the format with the help of the locale and not so explicitly, this PR could join forces with #305 to specify a localizable date-only format, for example:

dayjs('15/10/2018', { format: 'L', locale: 'pt-br' }).isValid()

Of course, you would have to know, that “L” means date-only and how it translates in Portuguese 😃

[iamkun]

From v1.8.7, you could check like this

import 'dayjs/locale/es'
import customParseFormat from 'dayjs/plugin/customParseFormat'
dayjs.extend(customParseFormat)

dayjs('2018 Enero 15', 'YYYY MMMM DD', 'es').isValid()