Setting Calendar and Date Systems

Note:

Currently in the beta phase.

Usage Scenarios

Users in different regions utilize various calendar systems. Most regions follow the Gregorian calendar, while some users adopt alternative calendars such as the Lunar calendar, Islamic calendar, or Hebrew calendar. Additionally, time and date representations vary across time zones and daylight saving time adjustments. Therefore, users should configure calendars that align with local conventions. The internationalization module provides the Calendar class, which enables setting calendar types, dates, year-month-day values, time zones, first day of the week, minimum days in the first week of the year, determining whether a specific date falls on a weekend, calculating day differences, and more. During application development, developers can select appropriate functions based on business requirements.

Development Steps

Using the example of converting Gregorian dates to Lunar calendar dates, this section demonstrates how to use the Calendar class interfaces.

1. Import the module.

   import kit.LocalizationKit.*
   

2. Gregorian calendar operations.

   let calendar: Calendar = getCalendar('zh-Hans', calendarType:  CalendarType.Chinese)
   // Set the time for the calendar object
   calendar.setTime(10540800000.0)
   
   // Set the calendar object's date to 2022.05.13 08:00:00
   calendar.set(2022, 5, 13, hour: 8, minute: 0, second: 0)
   
   // Set the time zone for the calendar object
   calendar.setTimeZone('Asia/Shanghai')
   
   // Get the time zone of the calendar object
   let timezone: String = calendar.getTimeZone() // timezone = 'Asia/Shanghai'
   
   // Get the first day of the week for the calendar object
   let firstDayOfWeek: Int32 = calendar.getFirstDayOfWeek() // firstDayOfWeek = 1
   
   // Set the first day of the week
   calendar.setFirstDayOfWeek(1)
   
   // Get the minimum days in the first week of the year
   let minimalDaysInFirstWeek: Int32 = calendar.getMinimalDaysInFirstWeek() // minimalDaysInFirstWeek = 1
   
   // Set the minimum days in the first week of the year
   calendar.setMinimalDaysInFirstWeek(3)
   
   // Get the value associated with the specified field in the calendar object
   let year: Int32 = calendar.get('year') // year = 2022
   
   // Get the localized name of the calendar object
   let calendarName: String = calendar.getDisplayName('zh-Hans') // calendarName = 'Gregorian Calendar'
   
   // Perform addition/subtraction operations on specified calendar fields
   calendar.set(2023, 10, 15)
   calendar.add('date', 2)
   let day: Int32 = calendar.get('date') // day = 17
   

3. Convert Gregorian dates to Lunar calendar dates.

   import std.time.DateTime as d
   
   let calendar: Calendar = getCalendar('zh-Hans', calendarType: CalendarType.Chinese)
   // Set Gregorian date information to the calendar object (2023.07.25 08:00:00)
   calendar.set(2023, 7,  25, hour:8, minute:0)
   // Get Lunar calendar year, month, and day
   let year: Int32 = calendar.get('year') // year = 40, representing the 40th year in the sexagenary cycle (range: 1-60)
   let month: Int32 = calendar.get('month') // month = 5, representing the 6th month
   let day: Int32 = calendar.get('date') // day = 8, representing the 8th day
   

Supported calendar types are as follows:

Type	Chinese Name
buddhist	Buddhist Calendar
chinese	Lunar Calendar
coptic	Coptic Calendar
ethiopic	Ethiopian Calendar
hebrew	Hebrew Calendar
gregory	Gregorian Calendar
indian	Indian National Calendar
islamic_civil	Islamic Civil Calendar
islamic_tbla	Islamic Tabular Calendar
islamic_umalqura	Umm al-Qura Calendar
japanese	Japanese Calendar
persian	Persian Calendar