Validating time

Is this fair enough to validate time for year 2009..

Code:

---

bool valid::validDayOfDate(const int& day)
{
        return (day>0) && (day<=31);
}

bool valid::validMonthOfDate(const int& month)
{
        return (month>0) && (month<=12);
}

bool valid::validYearOfDate(const int& year)
{
        return year==2009;
}

bool valid::validHourhOfDay(const int& hr)
{
  return (hr>=0) && (hr<24);
}

bool valid::validMinuteOfDay(const int& min)
{
        return (min>=0) && (min<60);
}

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Hi, I'm going to be honest here, I've never seen return values referenced in that way, aka:

Code:

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return (day>0) && (day<=31);

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Instead of:

Code:

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if (day > 0 && day <= 31)
  return 1;
else
  return 0;

---

But if that is a valid way of evaluation, and an if statement is not required, I cannot see any reason why that wouldn't work.

Not really. You've got to deal with days in February and leap years. Plus, September, April, June and November have only thirty days. Plus, theGregorian calendar was only well-known around the world after AD 1582, so choose an appropriate epoch for the year.

It would seem more convenient to validate 59 minutes and 59 seconds, since it wraps around to 0 anyway, but it depends on what's acceptable input I suppose. It makes perfect sense to time the microwave for 90 seconds and stuff, for example.

Get crackin'

Quote:

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Originally Posted by whiteflags

It would seem more convenient to validate 59 minutes and 59 seconds, since it wraps around to 0 anyway, but it depends on what's acceptable input I suppose. It makes perfect sense to time the microwave for 90 seconds and stuff, for example.

Get crackin'

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reason i'm saying '<60' ... caters for 59 not 60

Quote:

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Originally Posted by pobri19

Code:

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if (x < 5)
  return 1;
else
  return 0;

---

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same as

return x < 5;

You don't take into account that months have a different length.

It also doesn't seem worth it to make a function that only accepts one particular year. Are you going to recompile the application next year etc?

I have mostly avoided dealing with dates, but I'd rather use existing libraries, such as Boost.Datetime.

Quote:

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Plus, theGregorian calendar was only well-known around the world after AD 1582, so choose an appropriate epoch for the year.

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In the Russian Empire (and hence in my country) this happened as lately as on February 2, 1918. (This is the reason why the 1917 communist revolution a.k.a the October Revolution has always been celebrated in November :) )

In particular, since this country has been under various rules throughout the history, it also used Gregorian calendar for some time in the 17th-18th century if I'm not mistaken :) So dates far back in the history are relative to geographical locations.

Quote:

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Originally Posted by csonx_p

same as

return x < 5;

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Thanks, I'm surprised I haven't seen it used before like that :/

It would be surprising to see it otherwise :)

Quote:

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Originally Posted by whiteflags

Not really. You've got to deal with days in February and leap years.

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Not with the only valid year being 2009 - look at the validYearOfDate() function. :)

That one I will respond to. Were there ever more than 29 days in February? Certainly not in 2009.

I understand there' a function mktime() which can help me convert from tm to time_t, then i can calculate difference in seconds. But i have a unique situation here... A user shoul be able to enter two dates (start - end) manually in the format (month/day/year hour:minutes:seconds) ... Then is should first be able to convert from these start/end format to tm structure .. This is where my problem is...

Here's my attempt though

Code:

---

        struct tm issueDate;
        struct tm returnDate;

        /***
        **
        * Convert from normal date to TM structure
        **
        ***/

        std::ostringstream issue_dymonyr, return_dymonyr;
        std::ostringstream issue_hrminsec, return_hrminsec;

        issue_dymonyr << issue_dt.getMonth() << "/" << issue_dt.getDay() << "/" << issue_dt.getYear();
        return_dymonyr << return_dt.getMonth() << "/" << return_dt.getDay() << "/" << return_dt.getYear();
       
        issue_hrminsec << issue_dt.getHour() << ":" << issue_dt.getMinute() << ":" << "0";
        return_hrminsec << return_dt.getHour() << ":" << return_dt.getMinute() << ":" << "0";

        strptime(issue_dymonyr.str()+" "+issue_hrminsec.str(), "%D %T", &issueDate);
        strptime(return_dymonyr.str()+" "+return_hrminsec.str(), "%D %T", &returnDate);

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I have an error here, says : "error C3861: 'strptime': identifier not found" .. i have #include <time.h> added

Is there a reason you cannot use Boost?

Quote:

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Originally Posted by Elysia

Is there a reason you cannot use Boost?

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Please expand? I do have boost configure, which funcition do i need from boost.. Or which header file

thnx

If you would listen to feedback...

Quote:

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Originally Posted by anon

I have mostly avoided dealing with dates, but I'd rather use existing libraries, such as Boost.Datetime.

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Quote:

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Originally Posted by Elysia

Is there a reason you cannot use Boost?

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seem to be experiencing strange problems with the 'days' class from boost

Code:

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        using namespace boost::gregorian;

        std::ostringstream issue_dymonyr, return_dymonyr;
        std::ostringstream issue_hrminsec, return_hrminsec;

        issue_dymonyr << issue_dt.getMonth() << "-" << issue_dt.getDay() << "-" << issue_dt.getYear();
        return_dymonyr << return_dt.getMonth() << "-" << return_dt.getDay() << "-" << return_dt.getYear();

        try {
          date issuedDate(from_simple_string(issue_dymonyr.str()));
          date returnDate(from_simple_string(return_dymonyr.str()));
          days rental_days = returnDate - issuedDate; /* HERE ... Error : syntax error : missing ';' before identifier 'rental_days' */
            & /* error C2065: 'rental_days' : undeclared identifier */
        }
        catch(...) {
                std::cout << "Bad dates entered: " << issue_dymonyr.str() << return_dymonyr.str() << std::endl;
        }

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Is there such a type as "days"?

Quote:

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Originally Posted by Elysia

Is there such a type as "days"?

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Yep! Got it to compile now... One issue though, Is this function accurate? I mean should return_days calculation consider hours and minutes as well?

Code:

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void Contract::CalculateNoOfDays(Date issue_dt, Date return_dt)
{
        using namespace boost::gregorian;

        std::ostringstream issue_dymonyr, return_dymonyr;

        issue_dymonyr << issue_dt.getMonth() << "-" << issue_dt.getDay() << "-" << issue_dt.getYear();
        return_dymonyr << return_dt.getMonth() << "-" << return_dt.getDay() << "-" << return_dt.getYear();
       
        try {
          date issuedDate(from_simple_string(issue_dymonyr.str()));
          date returnDate(from_simple_string(return_dymonyr.str()));
          days rental_days = returnDate - issuedDate;
        }
        catch(...) {
                std::cout << "Bad date entered: " << issue_dymonyr.str() << return_dymonyr.str() << std::endl;
        }
}

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[EDIT}
Not forgetting how to convert from days to a normal integer value [/EDIT]

Quote:

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Originally Posted by csonx_p

Yep! Got it to compile now... One issue though, Is this function accurate? I mean should return_days calculation consider hours and minutes as well?

Code:

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void Contract::CalculateNoOfDays(Date issue_dt, Date return_dt)
{
        using namespace boost::gregorian;

        std::ostringstream issue_dymonyr, return_dymonyr;

        issue_dymonyr << issue_dt.getMonth() << "-" << issue_dt.getDay() << "-" << issue_dt.getYear();
        return_dymonyr << return_dt.getMonth() << "-" << return_dt.getDay() << "-" << return_dt.getYear();
       
        try {
          date issuedDate(from_simple_string(issue_dymonyr.str()));
          date returnDate(from_simple_string(return_dymonyr.str()));
          days rental_days = returnDate - issuedDate;
        }
        catch(...) {
                std::cout << "Bad date entered: " << issue_dymonyr.str() << return_dymonyr.str() << std::endl;
        }
}

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[EDIT}
Not forgetting how to convert from days to a normal integer value [/EDIT]

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this seems to compile

Code:

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int  contractDays = rental_days.days();

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Still worried about if the results are accurate since hours and minutes are not explicitly specified...

Maybe you want to take a look at the examples?
http://www.boost.org/doc/libs/1_37_0...te_period_calc
They might give you some insight. Be sure to consult the documentation for the classes, as well. There might be something there.

I am not familiar with Boost::DateTime, however, so I cannot say.