Retrieves locale-specific rules used to determine which day period to use when more than one period is defined for a locale.
getLocaleExtraDayPeriodRules(locale: string): (Time | [Time, Time])
A locale code for the locale format rules to use.
There is a rule for each defined day period. The first rule is applied to the first day period and so on. Fall back to AM/PM when no rules are available.
A rule can specify a period as time range, or as a single time value.
This functionality is only available when you have loaded the full locale data. See the "I18n guide".