getLocaleExtraDayPeriodRules
Rules used to determine which day period to use (See dayPeriods below). The rules can either be an array or a single value. If it's an array, consider it as "from" and "to". If it's a single value then it means that the period is only valid at this exact value. There is always the same number of rules as the number of day periods, which means that the first rule is applied to the first day period and so on. You should fallback to AM/PM when there are no rules available.
说明
Note: this is only available if you load the full locale data. See the "I18n guide" to know how to import additional locale data.
