C# - calculate number of days away from a deadline [improved]

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Hi,

I have been given the date and time of an appointment and I need to return how many days it (the appointment) is in the future. The answer must be in FULL days; for example, at 11 PM tonight, an appointment at 9 AM tomorrow would be 1 day (and not 10 hours).

I have attempted the question (please see the code below). However, I get a red squiggly line underneath everything, stating 'cannot implicitly convert type 'double' to 'int'. An explicit conversion exists (are you missing a cast?)'.

Please bear in mind that I am constantly doing other research to learn C#, and lazy is not what I am being by posting questions which I have attempted.

I appreciate your help.

Regards.

What I have tried:

C#

public static int HowManyDaysFromToday(DateTime appointment)
{
  return appointment.TimeOfDay.Subtract(DateTime.Now.TimeOfDay).TotalDays;
}

Posted 13-Jul-17 2:41am

Member 13302374

Updated 13-Jul-17 4:16am

Andy Lanng

v2

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Solution 2

This is basically the same issue as C# - calculate number of hours away from a deadline[^] except that this time you are looking at Days. Given that you want full or partial days you just need to divide the hours by 24 and add 1 if there is a remainder. Simple maths really.

Posted 13-Jul-17 4:16am

Richard MacCutchan

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Maciej Los 13-Jul-17 12:32pm

5ed!

Andy Lanng 14-Jul-17 4:10am

This mostly came up in the chat on the last question (your link): Basically if the dates cross midnight then that is a whole day, so 11pm - 9am is 1 day but 11am - 9pm isn't

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Andy Lanng · Accepted Answer · 2017-07-13T02:49:00

Well I'd suggest stripping the time out and compare the two dates that way:

C#

public static int HowManyDaysFromToday(DateTime appointment)
{
  var today = DateTime.Today; //like DateTime.Now but with no time aspect
  var appDay = appointment.Date;
  return appDay.Subtract(today).TotalDays;
}

If you wanted then you could return a timespan with the actual time too:

C#

public static TimeSpan HowManyDaysFromToday(DateTime appointment)
{
  var today = DateTime.Today; //like DateTime.Now but with no time aspect
  var appDay = appointment.Date;
  return appDay.Subtract(today) + appointment.Subtract(appDay); // or whatever
}

That way you have all the data in one standard object:

C#

public override string ToString(){
  var ts = HowManyDaysFromToday(_app);
  return string.Format("{0} days at {1}:{2}",(int)ts.TotalDays,ts.Hours,ts.Minutes);
}

That's not a great way to do it, but it's just an idea ^_^