得到当前年、月、周的第一天和最后一天

常规获取当前时间等操作就不在赘述。这里分享下自己写的关于得到当前年、月、周的第一天和最后一天的方法。

在.h文件里声明方法

@interface ZYModel : NSObject

+(ZYModel *)getInstance;

/** * 得到这个月的第一天和最后一天 */

- (NSArray*)getFirstAndLastDayOfMonth:(NSInteger)month inYear:(NSInteger)year;

/** * 得到今年的第一天和最后一天 */

- (NSArray*)getFirstAndLastDayOfYear:(NSInteger)year;

@end

在.m文件里实现

static ZYModel* hudInstance = nil;

@interface ZYModel()

@property (nonatomic,strong) NSArray * jiduArr;

@end

@implementation ZYModel

+(ZYModel *)getInstance{

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

hudInstance = [[ZYModel alloc] init];

});

return hudInstance;

}

-(NSArray*)getFirstAndLastDayOfMonth:(NSInteger)month inYear:(NSInteger)year {

NSArray * dateArr = [NSArray new];

dateArr = [self getjidumonth:month];

NSString * str1 = dateArr[0];

NSString * str2 = dateArr[2];

NSInteger firstteger = [str1 integerValue];

NSInteger lastteger = [str2 integerValue];

NSCalendar *calendar = [NSCalendar currentCalendar];

NSDate *date = [self getDateWithMonth:firstteger year:year];

NSDate *datelast = [self getDateWithMonth:lastteger year:year];

NSDate *firstDay;

NSTimeInterval interval;

[calendar rangeOfUnit:NSCalendarUnitMonth startDate:&firstDay interval:&interval forDate:date];

NSDate *last_Day;

NSTimeInterval interval_last;

[calendar rangeOfUnit:NSCalendarUnitMonth startDate:&last_Day interval:&interval_last forDate:datelast];

NSDateComponents *lastDateComponents = [calendar components:NSCalendarUnitMonth | NSCalendarUnitYear |NSCalendarUnitDay fromDate:last_Day];

NSUInteger dayNumberOfMonth = [calendar rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitMonth forDate:datelast].length;

NSInteger day = [lastDateComponents day];

[lastDateComponents setDay:day + dayNumberOfMonth];

lastDateComponents.nanosecond = lastDateComponents.nanosecond - 1000000;

NSDate *lastDay = [calendar dateFromComponents:lastDateComponents];

return [NSArray arrayWithObjects:firstDay,lastDay, nil];

}

-(NSArray*) getjidumonth:(NSInteger)month{

NSArray * dateArr = [NSArray new];

NSString * str = [NSString stringWithFormat:@"%ld",month];

for (int i = 0; i<self.jiduArr.count; i++){

NSArray * arr = self.jiduArr[i];

for (int j= 0; j<arr.count;j++){

if ([str isEqualToString:arr[j]]) {

dateArr = arr;

}

}

}

return dateArr;

}

- (NSDate *)getDateWithMonth:(NSInteger)month year:(NSInteger)year {

NSDateComponents *dateComponents = [[NSDateComponents alloc] init];

dateComponents.year = year;

dateComponents.month = month;

NSCalendar *calendar = [NSCalendar currentCalendar];

NSDate *date = [calendar dateFromComponents:dateComponents];

return date;

}

+ (NSArray*)getFirstAndLastDayOfYear:(NSInteger)year {

NSDate *date = [self getDateWithYear:year];

NSCalendar *calendar = [NSCalendar currentCalendar];

NSDate *firstDay;

[calendar rangeOfUnit:NSCalendarUnitYear startDate:&firstDay interval:nil forDate:date];

NSDateComponents *lastDateComponents = [calendar components:NSCalendarUnitMonth | NSCalendarUnitYear | NSCalendarUnitDay fromDate:firstDay];

NSUInteger dayNumberOfYear = [calendar rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitYear forDate:date].length;

NSInteger day = [lastDateComponents day];

[lastDateComponents setDay:day + dayNumberOfYear];

lastDateComponents.nanosecond = lastDateComponents.nanosecond - 1000000;

NSDate *lastDay = [calendar dateFromComponents:lastDateComponents];

return [NSArray arrayWithObjects:firstDay,lastDay, nil];

}

+ (NSDate *)getDateWithYear:(NSInteger)year {

NSDateComponents *dateComponents = [[NSDateComponents alloc] init];

dateComponents.year = year;

NSCalendar *calendar = [NSCalendar currentCalendar];

NSDate *date = [calendar dateFromComponents:dateComponents];

return date;

}

-(NSArray*)jiduArr{

if (_jiduArr == nil) {

_jiduArr = @[@[@"1",@"2",@"3"],

@[@"4",@"5",@"6"],

@[@"7",@"8",@"9"],

@[@"10",@"11",@"12"]

];

}

return _jiduArr;

}

@end

在要获取操作的地方 进行处理 eg：获取一个季度的开始日期和结束日期

- (void)viewDidLoad {

[super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib.

NSArray* dateArray = [NSArray new];

dateArray = [[ZYModel getInstance] getFirstAndLastDayOfMonth:10 inYear:2017];

NSDate * date1 = [dateArray objectAtIndex:0];

NSDate * date2 = [dateArray objectAtIndex:1];

NSString * StrDate1 = [self getdateStr:date1];

NSString * StrDate2 = [self getdateStr:date2];

NSLog(@"dat1==%@  date2==%@",StrDate1,StrDate2);

}

-(NSString*)getdateStr:(NSDate*)date{

NSDateFormatter *dateFormatter=[[NSDateFormatter alloc]init];//创建一个日期格式化器

dateFormatter.dateFormat=@"yyyy-MM-dd ";//指定转date得日期格式化形式

return [dateFormatter stringFromDate:date];//2015-11-20 08:24:04

}