两个NSDate对象之间的天数

我想比较两天的NSDate对象，我第一次使用NSDateComponents来计算我的两个date对象之间的差异，但它工作正常。

NSString *dateStr =@"2012-11-05 15:00:00"; NSDate *date = [dateFormat dateFromString:dateStr]; NSDateComponents *datesDiff = [calendar components: NSDayCalendarUnit fromDate: date toDate: [NSDate date] options: 0]; 

这不能解决我的问题。 实际上，当date1 = 2012-11-05 23:00:00和date2 = 2012-11-06 10:00:00时，两个date之间的差异是0天和11个小时。 我正在寻找一些东西，可以让我检测一天的变化，换句话说，当date1 = 2012-11-05 23:00:00和date2 = 2012-11-06 00:01:00，有一天差异。

如果有人知道解决scheme，我会欢迎他的build议。 提前致谢

Answer 1

我想你正在寻找这个（从date和时间编程指南 ）：

清单13两个date之间的天数，就像中午之间的天数一样

 @implementation NSCalendar (MySpecialCalculations) -(NSInteger)daysWithinEraFromDate:(NSDate *) startDate toDate:(NSDate *) endDate { NSInteger startDay=[self ordinalityOfUnit:NSDayCalendarUnit inUnit: NSEraCalendarUnit forDate:startDate]; NSInteger endDay=[self ordinalityOfUnit:NSDayCalendarUnit inUnit: NSEraCalendarUnit forDate:endDate]; return endDay-startDay; } @end 

编辑：迅捷版本：

 extension NSCalendar { func daysWithinEraFromDate(startDate: NSDate, endDate: NSDate) -> Int { let startDay = self.ordinalityOfUnit(.Day, inUnit: NSCalendarUnit.Era, forDate: startDate) let endDay = self.ordinalityOfUnit(.Day, inUnit: NSCalendarUnit.Era, forDate: endDate) return endDay - startDay } } 

Answer 2

 NSString *start = @"2010-09-01"; NSString *end = @"2010-12-01"; NSDateFormatter *f = [[NSDateFormatter alloc] init]; [f setDateFormat:@"yyyy-MM-dd"]; NSDate *startDate = [f dateFromString:start]; NSDate *endDate = [f dateFromString:end]; [f release]; NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDateComponents *components = [gregorianCalendar components:NSDayCalendarUnit fromDate:startDate toDate:endDate options:0]; [gregorianCalendar release]; 

组件现在保持不同。

 NSLog(@"%ld", [components day]); 

Answer 3

 func daysBetweenDates(startDate: NSDate, endDate: NSDate) -> Int { let calendar = NSCalendar.currentCalendar() let components = calendar.components([.Day], fromDate: startDate, toDate: endDate, options: []) return components.day } 

要么

 let calendar = NSCalendar.currentCalendar(); let component1 = calendar.component(.Day, fromDate: fromDate) let component2 = calendar.component(.Day, fromDate: toDate) let difference = component1 - component2 

Answer 4

对于Swift 3：

从@ masa的回答扩展：

 extension Calendar { func daysWithinEraFromDate(startDate: Date, endDate: Date) -> Int? { guard let startDay = ordinality(of: .day, in: .era, for: startDate) else { return nil } guard let endDay = ordinality(of: .day, in: .era, for: endDate) else { return nil } return endDay - startDay } }