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date calculationsI am creating a program that involves having to find the difference between
two dates and converting it to a number to be used for calculations. The problem is that the way it is setup, VB is not doing anything with the dates that I have selected. I hope that someone here can help me figure out why it is not working what I have to do to make it work. This the code I have for the date calculations. txtNumberOfDays.text = Val(dateTimeCheckout.Value.Date.ToString()) - Val(dateTimeArrival.Value.Date.ToString) try this instead:
txtNumberOfDays.text = datediff(days,dateTimeCheckout,dateTimeArrival).tostring "Charlie Brookhart" <charliebrookhar***@hotmail.com> wrote in You can also do:news:JsydnQ-lC56jftPZnZ2dnUVZ_sCdnZ2d@adelphia.com: > I am creating a program that involves having to find the difference > between two dates and converting it to a number to be used for > calculations. The problem is that the way it is setup, VB is not doing > anything with the dates that I have selected. I hope that someone here > can help me figure out why it is not working what I have to do to make > it work. > > This the code I have for the date calculations. EndDate.Substract(StartDate) It'll return a TimeSpan object which has a variety of caluations (from total days, total minutes, etc). So, if I use EndDate.Subtract(StartDate), then it would look like this:
txtNumberOfDays = EndDate.Subtract(StartDate) ? Would that return a whole number value like 3 days or 5 days? Show quoteHide quote "Spam Catcher" <spamhoneypot@rogers.com> wrote in message news:Xns97B1427E74A8usenethoneypotrogers@127.0.0.1... > "Charlie Brookhart" <charliebrookhar***@hotmail.com> wrote in > news:JsydnQ-lC56jftPZnZ2dnUVZ_sCdnZ2d@adelphia.com: > > > I am creating a program that involves having to find the difference > > between two dates and converting it to a number to be used for > > calculations. The problem is that the way it is setup, VB is not doing > > anything with the dates that I have selected. I hope that someone here > > can help me figure out why it is not working what I have to do to make > > it work. > > > > This the code I have for the date calculations. > > > You can also do: > > > EndDate.Substract(StartDate) > > It'll return a TimeSpan object which has a variety of caluations (from > total days, total minutes, etc). This method does not work because dateddiff and days are not declared.
txtNumberOfDays.text = datediff(days,dateTimeCheckout,dateTimeArrival).tostring _________________________________________ This method does not work because EndDate and StartDate are not declared. EndDate.Subtract(StartDate) Show quoteHide quote "Charlie Brookhart" <charliebrookhar***@hotmail.com> wrote in message news:h62dnRLIetPjZdPZRVn-qQ@adelphia.com... > So, if I use EndDate.Subtract(StartDate), then it would look like this: > > txtNumberOfDays = EndDate.Subtract(StartDate) ? Would that return a whole > number value like 3 days or 5 days? > > "Spam Catcher" <spamhoneypot@rogers.com> wrote in message > news:Xns97B1427E74A8usenethoneypotrogers@127.0.0.1... > > "Charlie Brookhart" <charliebrookhar***@hotmail.com> wrote in > > news:JsydnQ-lC56jftPZnZ2dnUVZ_sCdnZ2d@adelphia.com: > > > > > I am creating a program that involves having to find the difference > > > between two dates and converting it to a number to be used for > > > calculations. The problem is that the way it is setup, VB is not doing > > > anything with the dates that I have selected. I hope that someone here > > > can help me figure out why it is not working what I have to do to make > > > it work. > > > > > > This the code I have for the date calculations. > > > > > > You can also do: > > > > > > EndDate.Substract(StartDate) > > > > It'll return a TimeSpan object which has a variety of caluations (from > > total days, total minutes, etc). > > Try this:
Dim ts As TimeSpan ts = EndDate.Subtract(StartDate) txtNumberOfDays.Text = ts.Days There are other properties of the TimeSpan object as well Charlie,
There are in VB endless methods to handles dates. But no methods to calculate with strings as you do. Your instruction is in fact like this. txtNumberOfDays.text = Val("Apples" - "Pears") You can look at the datediff method, but better to the timespan methods. Be aware that you are comparing with this exact complete days is less than a million, so you have to decide yourself if a day plus some milliseconds is one day or two. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemtimespanclasstopic.asp http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemtimespanclassdaystopic.asp I hope this helps, Cor Charlie Brookhart wrote:
> I am creating a program that involves having to find the difference between If it's not doing anything with the dates, your code is simply not > two dates and converting it to a number to be used for calculations. The > problem is that the way it is setup, VB is not doing anything with the dates > that I have selected. I hope that someone here can help me figure out why it > is not working what I have to do to make it work. > > This the code I have for the date calculations. > > txtNumberOfDays.text = Val(dateTimeCheckout.Value.Date.ToString()) - > Val(dateTimeArrival.Value.Date.ToString) > > executed at all. It has do be doing something, but I imagine nothing useful. You shouldn't convert the dates to strings and back to numbers, as the string representation of a date can not be interpreted as a single number. You should use the methods of the DateTime class for comparing the dates. Use the Subtract method and you will get a TimeSpan object, from which you can get the difference between the dates most any way you like. For an example: txtNumberOfDays.text = dateTimeCheckout.Value.Date.Subtract(dateTimeArrival.Value.Date).TotalDays.ToString() Goran:
Thanks for your suggestion. I will give it a try. Cor: You say that my instructions are the equivalent of txtNumberOfDays.text = Val("Apples" - "Pears"). What I don't understand is why doesn't VB see the instructions I have as a value that I am trying to get, especially when I start out using Val and then more specifically indicate that I want to get a date value and subtract that value from another date value? Show quoteHide quote "Göran Andersson" <gu***@guffa.com> wrote in message dateTimeCheckout.Value.Date.Subtract(dateTimeArrival.Value.Date).TotalDays.Tnews:e73b7hQaGHA.3992@TK2MSFTNGP05.phx.gbl... > Charlie Brookhart wrote: > > I am creating a program that involves having to find the difference between > > two dates and converting it to a number to be used for calculations. The > > problem is that the way it is setup, VB is not doing anything with the dates > > that I have selected. I hope that someone here can help me figure out why it > > is not working what I have to do to make it work. > > > > This the code I have for the date calculations. > > > > txtNumberOfDays.text = Val(dateTimeCheckout.Value.Date.ToString()) - > > Val(dateTimeArrival.Value.Date.ToString) > > > > > > If it's not doing anything with the dates, your code is simply not > executed at all. > > It has do be doing something, but I imagine nothing useful. You > shouldn't convert the dates to strings and back to numbers, as the > string representation of a date can not be interpreted as a single number. > > You should use the methods of the DateTime class for comparing the > dates. Use the Subtract method and you will get a TimeSpan object, from > which you can get the difference between the dates most any way you > like. For an example: > > txtNumberOfDays.text = > oString() Carlie,
The Val method is rarely used. It returns from a string an undefined value. ToString is a method that is in any object. And everyhing in VBNet is an object. If it is overriden it can return a string of numbers. However from which the value says not much. . If you want to calculate with dates, than you have almost forever to use dates in net. Even when you say A = Cdate("01-01-2000")-Cdate("12-12-1999") you are calculating with dates. The basic of your solution by the way is in the message from Chris Dunaway, I hope this helps, Cor Show quoteHide quote "Charlie Brookhart" <charliebrookhar***@hotmail.com> schreef in bericht news:Ba2dnfCoA46gFtLZnZ2dnUVZ_s-dnZ2d@adelphia.com... > Goran: > > Thanks for your suggestion. I will give it a try. > > Cor: > > You say that my instructions are the equivalent of txtNumberOfDays.text = > Val("Apples" - "Pears"). What I don't understand is why doesn't VB see the > instructions I have as a value that I am trying to get, especially when I > start out using Val and then more specifically indicate that I want to get > a > date value and subtract that value from another date value? > > "Göran Andersson" <gu***@guffa.com> wrote in message > news:e73b7hQaGHA.3992@TK2MSFTNGP05.phx.gbl... >> Charlie Brookhart wrote: >> > I am creating a program that involves having to find the difference > between >> > two dates and converting it to a number to be used for calculations. >> > The >> > problem is that the way it is setup, VB is not doing anything with the > dates >> > that I have selected. I hope that someone here can help me figure out > why it >> > is not working what I have to do to make it work. >> > >> > This the code I have for the date calculations. >> > >> > txtNumberOfDays.text = Val(dateTimeCheckout.Value.Date.ToString()) - >> > Val(dateTimeArrival.Value.Date.ToString) >> > >> > >> >> If it's not doing anything with the dates, your code is simply not >> executed at all. >> >> It has do be doing something, but I imagine nothing useful. You >> shouldn't convert the dates to strings and back to numbers, as the >> string representation of a date can not be interpreted as a single >> number. >> >> You should use the methods of the DateTime class for comparing the >> dates. Use the Subtract method and you will get a TimeSpan object, from >> which you can get the difference between the dates most any way you >> like. For an example: >> >> txtNumberOfDays.text = >> > dateTimeCheckout.Value.Date.Subtract(dateTimeArrival.Value.Date).TotalDays.T > oString() > > 
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