I want to determine day, month, and year of current date in iOS. I found this after a search on the net:
NSDate *date = [NSDate date];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [calendar components:(NSDayCalendarUnit) fromDate:date];
NSInteger Day = [components day];
NSInteger month = [components month];
NSInteger year = [components year];
This code shows the day correct, but the year and month is not showing as it should be. It shows some digits like 2147483647. I could not find a solution so please help me correct the code I found, or write some new code which does what I need.
This line is the problem:
NSDateComponents *components = [calendar components:(NSDayCalendarUnit) fromDate:date];
It should be
NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:date];
Related
How can I create an NSDate with today's date and an hour, minutes, and seconds of 5, 0, and 0 respectively? I.e. the date will be 07/02/2010 05:00:00
//Gives us the current date
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorian components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:[NSDate date]];
[components setHour:5];
NSDate * date = [gregorian dateFromComponents:components];
[gregorian release];
Something along those lines should do the trick.
I am working on a Calender app and it's working fine when i navigate to next month as i am able to get the last day of the month and from where i am able to get the first day of coming month .but when i navigate to previous month i m not able to get the last month's first day.Is there any way to get first day of last month.
The following works fine for me
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDate *currentDate = [NSDate date];
NSDateComponents *components = [calendar components:(NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:currentDate];
components.month = components.month - 1;
components.day = 1;
NSDate *newDate = [calendar dateFromComponents:components];
This also works if your current month is january. NSDateComponents will automatically decrement the year and set the month to december.
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear
fromDate:[NSDate date]];
components.day = 1;
components.month = components.month - 1;
NSDate *lastmonthDay1 = [[NSCalendar currentCalendar] dateFromComponents: components];
NSLog(#"First day of last month====: %#", [lastmonthDay1 descriptionWithLocale:[NSLocale currentLocale]]);
You can do something like below....
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"UTC"]];
NSDateComponents *comp = [gregorian components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:[NSDate date]];
[comp setDay:1];
[comp setMonth:CurrentMonth];//previous month
[comp setYear:currentYear];
NSDate *firstDayOfMonthDate = [gregorian dateFromComponents:comp];
NSCalendar *cal1=[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comps1 = [cal1 components:NSWeekdayCalendarUnit fromDate:firstDayOfMonthDate];
// 1 for mon 8 for sun
int startWithDay=[comps1 weekday]==1?8:[comps1 weekday];
//1 for monday
// 2 for tuesday and so on....
Let me know it is working or not!!!
Happy Coding!!!!
I am writing an alarm app. In the app user can select days for setting alarm on that day with time. But I don't know to set UILocalNotification for specific day in a week.
How I know about repeat interval. I know that I must to set
How to calculate how many days will come Friday?
How to Get an NSDate for a Specific Day of Week and Time from an Existing NSDate - this article will help you with this problem. You can get NSDate from current Friday with:
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setLocale:[NSLocale currentLocale]];
NSDateComponents *nowComponents = [gregorian components:NSYearCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:today];
[nowComponents setWeekday:6];
[nowComponents setWeek: [nowComponents week]]; // Current week
[nowComponents setHour:8]; // 8a.m.
[nowComponents setMinute:0];
[nowComponents setSecond:0];
NSDate *thisWeekFriday = [gregorian dateFromComponents:nowComponents];
Then, you may want to check if thisWeekFriday is less than [NSDate date], and get the next Friday if it is. You can move date by one week with:
NSDateComponents *components = [[NSDateComponents alloc] init];
components.week = 1;
NSDate *nextWeekFriday = [gregorian dateByAddingComponents:components toDate:thisWeekFriday options:0];
You can calculate the number of days between two dates like this:
NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:NSDayCalendarUnit
fromDate:today
toDate:futureDate
options:0];
NSInteger daysBetweenDates = dateComponents.day;
How to get the first day of a week for a date
this seems more easy at it is, since :
when the week starts with sunday, i need to get back the sunday date
if it starts on monday, i need to get the monday date
the input date is any date in week with time... i tried several approaches, but the edge case make it difficould
i made a function, which however doesn't work in 100% (not sure about the [components setDay: -weekday + 2];)
- (NSDate *)firstDateOfWeek {
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDateComponents *weekdayComponents = [calendar components:(NSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:self];
// because sunday is 0, we need it to be 6
NSInteger weekday = (([weekdayComponents weekday] + 6) % 7);
NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:self];
[components setDay: -weekday + 2];
return [calendar dateFromComponents:components];
}
It is easier to use the rangeOfUnit calendar method, which handles "start of the week" correctly according to the current locale:
NSDate *date = your date;
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDate *startOfWeek;
[calendar rangeOfUnit:NSWeekOfYearCalendarUnit
startDate:&startOfWeek
interval:NULL
forDate:date];
Using NSDateComponents, it would work as follows (assuming that a week has 7 days):
NSDate *date = your date;
NSDateComponents *comp = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSWeekdayCalendarUnit
fromDate:date];
NSDate *startOfDay = [calendar dateFromComponents:comp];
NSInteger diff = (NSInteger)[calendar firstWeekday] - (NSInteger)[comp weekday];
if (diff > 0)
diff -= 7;
NSDateComponents *subtract = [[NSDateComponents alloc] init];
[subtract setDay:diff];
NSDate *startOfWeek = [calendar dateByAddingComponents:subtract toDate:startOfDay options:0];
I'm getting a 0 for the month when I try to get the date difference from now and the end of the year. I'm using a NSCalendar object to get the difference between two NSDate objects.
NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setYear:2013];
[comps setMonth:0];
[comps setDay:0];
[comps setHour:0];
[comps setMinute:0];
[comps setSecond:0];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *newDate = [calendar dateFromComponents:comps];
NSDateComponents *timeDifference = [[NSCalendar currentCalendar]
components: NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit |
NSMinuteCalendarUnit | NSSecondCalendarUnit
fromDate:[NSDate date] toDate:newDate options:0];
int months = timeDifference.month;
int days = timeDifference.day;
if (months>0)
days+=31;
int hours = timeDifference.hour;
int minutes = timeDifference.minute;
int seconds = timeDifference.second;
You're trying to calculate number of months, days, etc to year 2013. In NSDateComponents 0 means 'no value', all values that count should be greater than 0. That's why your comps value is considered as 'incomplete', which causes strange output from NSCalendar.
Set month and day in lines 3-4 to 1 fix the issue.