iOS获取当前时间及前一天或后一天时间

NSDate * date
= [NSDate
date];//当前时间

NSDate *lastDay = [NSDate dateWithTimeInterval:-24*60*60 sinceDate:date];//前一天

NSDate *nextDay = [NSDate dateWithTimeInterval:24*60*60 sinceDate:date];//后一天

NSDictionary * timeDic =
@{@"beginTime":[Utility
timeStringFromFormat:@"yyyy-MM-dd"
withDate:lastDay],@"endTime":[Utility
timeStringFromFormat:@"yyyy-MM-dd"
withDate:nextDay]};