IOS Date Processing and ios Date Processing

IOS Date Processing and ios Date Processing

To obtain accurate time from a string, you must specifyCorrect Format StringAnd the correspondingTime zone ID

1. Date Format

1. Year

• yDisplay the year (0-9) as a number without leading zero
• yyDisplays the year in the format of two digits with leading zeros.
• yyyDisplay the year in four-digit format
• yyyyDisplay the year in four-digit format

2. Month

• MDisplay the month as a number without leading zero (for example, January 1, January is expressed as 1)
• MMDisplay the month as a number with a leading zero (for example, 01/12/01)
• MMMDisplay the month as an abbreviation (for example, Jan)
• MMMMDisplay the month as the complete month name (for example, January)
  • Jan January
  • Feb February
  • Mar March, March
  • Apr April
  • May
  • June Jun June
  • July Jul July
  • Aug August, August
  • Sep September
  • October, October
  • Nov November, November
  • December, December

3. Day

• dDisplay the day as a number without leading zero (for example, 1)
• ddDisplay the day as a number with a leading zero (for example, 01)

4. Weeks

• EEEDisplay Day as an abbreviation (for example, Sun)
• EEEEDisplay day as full name (for example, Sunday)
  • Mon Monday
  • Tuesday Tue Tuesday
  • Wed Wednesday
  • Thu Thursday
  • Friday Fri Friday
  • Saturday
  • Sunday Sun

5. Hours

• hUse the 12-hour system to display the hour as a number without leading zero (for example, 1:15:15)
• hhDisplay the hour as a number with a leading zero (for example, 01:15:15) in 12-hour format)
• HUse the 24-hour system to display the hour as a number without leading zero (for example, 1:15:15)
• HHDisplay the hour as a number with a leading zero (for example, 01:15:15) in the 24-hour format)

6. Minutes

• mDisplay the minute as a number without leading zero (for example)
• mmDisplay minutes as numbers with leading zeros (for example, 12:01:15)

7. Seconds

• sDisplay the second as a number without leading zero (for example)
• ssDisplay seconds as numbers with leading zeros (for example, 12:15:05)
• fDisplays the decimal part of a second.
• ffDisplay to 1% seconds
• ffffDisplay the data in exactly one thousandth of a second
• Up to seven f characters can be used in user-defined formats

8. Morning and afternoon

• t12-hour format
  • An upper-case A is displayed for any hour before noon.
  • An uppercase P value is displayed for any hour between noon and PM.
• ttFor regions in the 12-hour format
  • The upper-case AM is displayed for any hour before noon.
  • An uppercase PM is displayed for any hour between noon and PM.
• For regions in the 24-hour format, no characters are displayed.

9. Time Zone

• zDisplay Time Zone offset without leading zero
• zzDisplay the time zone offset with leading zero (for example,-08)
• zzzDisplay the complete time zone offset (for example,-0800)

10. Example

/// Create date based on the specified date string /// dateSring date string // The format of the date string is: "Sun May 24 13:59:03 + 0800 2015" class func createDate (dateSring: string)-> NSDate? {Let df = NSDateFormatter () df. locale = NSLocale (localeIdentifier: "ch") df. dateFormat = "eee mmm dd HH: mm: ss zzz yyyy" return df. dateFromString (dateSring )}

2. Create a category for NSDate

/// Parse from String to accurate time // The dateString parameter is the time String formatString. The formatString format is class func getDate (dateString: String, formatString: String)-> NSDate? {// DateFormatter // 1. instantiate let df = NSDateFormatter () // 2. to specify the region of the date, Xcode 6.3 beta is not required. You must specify the English language for the region. // Note: When debugging a real machine, you must specify the region, otherwise, df cannot be converted in previous versions. locale = NSLocale (localeIdentifier: "en") // 3. set the date format df. dateFormat = formatString // 4. generation date return df. dateFromString (dateString )}

3. Date Processing class NSCalendar

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