比较日期精确到日
+(BOOL)isOver{
//2013年12月31日23:59分后不再显示
NSDate* now = [NSDate date];
NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
[dateComponents setYear:2013];
[dateComponents setMonth:12];
[dateComponents setDay:31];
[dateComponents setHour:23];
[dateComponents setMinute:59];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate* endDate = [gregorian dateFromComponents:dateComponents];
if([now compare:endDate] == NSOrderedAscending)
{
return NO;
}
return YES;
}