Re: Best way to parse a time today?
Re: Best way to parse a time today?
- Subject: Re: Best way to parse a time today?
- From: Roger Dalal <email@hidden>
- Date: Wed, 12 Oct 2011 22:01:04 -0400
Dave:
Would it be possible for you to present an improved approach, please? I use this solution frequently, and have not yet encountered any issues, but now you have me worried! What approach do you suggest?
Roger Dalal
On Oct 12, 2011, at 9:49 PM, Dave DeLong wrote:
> Be careful with this approach, since there are some weird edge cases where that time may not exist on the proposed day (think DST boundaries).
>
> Dave
>
> Sent from my iPhone
>
> On Oct 12, 2011, at 6:46 PM, Roger Dalal <email@hidden> wrote:
>
>> Rick:
>>
>> The following code, which is likely what you are doing, will return the time in 1970 (NSDate's reference date) because you have not specified a date:
>>
>> NSString *timeString = @"14:50 PDT";
>> NSDateFormatter *df = [[NSDateFormatter alloc ] init];
>> [df setDateFormat:@"HH':'mm zzz"];
>> NSDate *date = [df dateFromString:timeString];
>> [df release];
>>
>>
>> Instead, you need to use date components to set the day as well as the time, per the following:
>>
>> NSString *timeString = @"14:50 PDT";
>> NSDateFormatter *df = [[NSDateFormatter alloc ] init];
>> [df setDateFormat:@"HH':'mm zzz"];
>> NSDate *date = [df dateFromString:timeString];
>>
>> NSCalendar *calendar = [NSCalendar currentCalendar];
>> NSDateComponents *dateComponents = [calendar components:( NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit ) fromDate:[NSDate date]];
>> NSDateComponents *timeComponents = [calendar components:( NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate: date ];
>>
>> [dateComponents setHour:[timeComponents hour]];
>> [dateComponents setMinute:[timeComponents minute]];
>> [dateComponents setSecond:[timeComponents second]];
>>
>> NSDate *timeToday = [calendar dateFromComponents:dateComponents];
>> [df release];
>>
>> Change 'fromDate' in NSDateComponents *dateComponents to whatever date you want in order to create your time on a different day.
>>
>> Best Wishes.
>>
>> Roger Dalal
>>
>>
>>
>>
>> On Oct 12, 2011, at 9:30 PM, Rick Mann wrote:
>>
>>> I have a situation where I have to parse times like "14:50 PDT". If I just set up an NSDateFormatter with dateFormat = @"HH:mm z", I end up with a time of day in 1970.
>>>
>>> What's the best way to get it to give me that time of day today?
>>>
>>> Thanks,
>>> Rick
>>>
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