iOS format specification
Directory
Overview
Date format
Declaration Time format: NSDateFormatter *date_formatter = [[NSDateFormatter alloc] init];
Set value time format: [Date_formatter setdateformat:@ "yyyy mm month DD day hh" mm min ss seconds "];
Set value Locale:[date_formatter Setlocale:[[nslocale alloc] initwithlocaleindentifier:@ "en_US"] or [date_formatter Setlocale:[nslocale Currentlocale]];
Date obtained
Get current date: nsdate *current_date = [NSDate Date];
Date obtained from string: nsdate *custom_date = [Date_formatter stringfromdate:@ "20140905133212"];
Convert the acquisition date to a string in the appropriate format: nsstring *str = [Date_formatter stringfromdate:current_date];
NSDateFormatter Format Description
G: A.D., e.g. AD A.D.
YY: The latter 2 digits of the year
YYYY: Full year
MM: Month, display as 1-12
MMM: Month, abbreviated for the English month, such as Jan
MMMM: Month, display full name of the English month, such as January
DD: day, 2 digits, such as 2
D: Day, 1-2-bit display, such as 2
EEE: Abbreviated day of the week, such as Sun
EEEE: Full written day of the week, such as Sunday
AA: Last afternoon, AM/PM
H: When, 24-hour, 0-23
K: When, 12-hour, 0-11
M: minutes, 1-2-bit
MM: Min., 2-bit
S: seconds, 1-2 bits
SS: Seconds, 2 bits
S: MS
Common date Structure
YYYY-MM-DD HH:mm:ss.sss
YYYY_MM-DD HH:mm:ss
Yyyy-mm-dd
MM DD yyyy
Customize the displayed week format
When using the NSDateFormatter conversion date, the day of the week that gets the English alphabet can only be like this, such as sun, Mon, etc.
If you want the day of the week for capital letters, you can:
Nsarray*weekdayary = [Nsarray arraywithobjects:@ "SUN", @ "MON", @ "TUE", @ "WED", @ "THU", @ "FRI", @ "SAT", nil];
Dateformatter = [[NSDateFormatter alloc] init];
[Dateformatter setdateformat:nslocalizedstring (@ "YYYY. MM.dd.eee ", nil)];
Change the day of the week of the uppercase letters displayed here? [Dateformattersetshortweekdaysymbols:weekdayary];
[Dateformatter setlocale:[[nslocale alloc]initwithlocaleidentifier:@ "en_US"]];
Nstring *str= [dateformatter stringfromdate:[nsdate Date]];
Calculate distance How much time is there in a day
nsdate* toDate = [[NSDate alloc]initwithstring:@ "2012-9-29 0:0:00 +0600"];
nsdate* startdate = [[Nsdatealloc] init];
nscalendar* Chineseclendar = [[Nscalendar alloc]initwithcalendaridentifier:nsgregoriancalendar];
Nsuinteger unitflags =
Nshourcalendarunit | Nsminutecalendarunit | Nssecondcalendarunit | Nsdaycalendarunit | Nsmonthcalendarunit | Nsyearcalendarunit;
Nsdatecomponents *cps = [Chineseclendar components:unitFlagsfromDate:startDate todate:todate options:0];
Nsinteger diffhour = [cps hour];
Nsinteger diffmin = [Cpsminute];
Nsinteger diffsec = [cps second];
Nsinteger diffday = [cps day];
Nsinteger Diffmon = [cps month];
Nsinteger diffyear = [cps year];
NSLog (@ "from-now-%@, diff:years:%d Months:%d, days;%d, Hours:%d, mins:%d,sec:%d",
[toDate description], diffyear, Diffmon, Diffday, diffhour,diffmin,diffsec);
iOS format specification