DateDiff Function

[cmdolcet69]

I'm trying to use the DateDiff function to calculate the difference
whether a shift has been setup. when i run the code below with
strFirstShiftEn d as a stringor date or datetime. I get an error
Argument Date1 cannot be converted to type Date. an anyone clear this
up.

If DateDiff("n", Format(Now, "hh:mm AMPM"), Format(strFirst ShiftEnd,
"hh:mm AMPM")) <= 0 Then
'logout
MsgBox("A shift change has occurred. You will be logged
out now.")
End If

[J.B. Moreno]

cmdolcet69 <co************ @hotmail.comwro te:

I'm trying to use the DateDiff function to calculate the difference
whether a shift has been setup. when i run the code below with
strFirstShiftEn d as a stringor date or datetime. I get an error
Argument Date1 cannot be converted to type Date. an anyone clear this
up.

If DateDiff("n", Format(Now, "hh:mm AMPM"), Format(strFirst ShiftEnd,
"hh:mm AMPM")) <= 0 Then
'logout
MsgBox("A shift change has occurred. You will be logged
out now.")
End If

Well, the obvious problem is that Format returns a string, not a
DateTime, which is what DateDiff requires.

After that, there's the question of what you were trying to do with the
Format, but that would require more info...

--
J.B. Moreno

[Armin Zingler]

"cmdolcet69 " <co************ @hotmail.comsch rieb

I'm trying to use the DateDiff function to calculate the difference
whether a shift has been setup. when i run the code below with
strFirstShiftEn d as a stringor date or datetime. I get an error
Argument Date1 cannot be converted to type Date. an anyone clear
this up.

If DateDiff("n", Format(Now, "hh:mm AMPM"), Format(strFirst ShiftEnd,
"hh:mm AMPM")) <= 0 Then
'logout
MsgBox("A shift change has occurred. You will be logged
out now.")
End If

Never use Strings to try to calculate with. Use the Date and TimeSpan data
types to store these values. Convert to/from String only if needed, e.g. for
visual display/input or file I/O.

An example:

Dim d1, d2 As Date
Dim ts As TimeSpan

d1 = Date.Parse(Inpu tBox("enter a date"))
d2 = Now
ts = d1.Subtract(d2)

MsgBox("Differe nce is: " & ts.TotalMinutes & " minutes")

So,
- Date (actually DateTime) stores any point in time (which does not have a
duration).
- TimeSpan stores the, surprise, time span between two points in time. You
can get the duration in any unit you want by accessing the Timespan's
members.
Armin

[Cor Ligthert[MVP]]

Or in version 2008 with option strict and infer on

\\\
Dim d1 = Date.Parse(Inpu tBox("Enter a date"))
Dim d2 = Now
Dim ts = d1.Subtract(d2)
MessageBox.Show ("Difference is: " & ts.TotalMinutes & " minutes")
///

Cor

Dim d1, d2 As Date
Dim ts As TimeSpan

d1 = Date.Parse(Inpu tBox("enter a date"))
d2 = Now
ts = d1.Subtract(d2)

MsgBox("Differe nce is: " & ts.TotalMinutes & " minutes")

[cmdolcet69]

On Dec 24, 5:16*am, "Armin Zingler" <az.nos...@free net.dewrote:

"cmdolcet69 " <colin_dolce... @hotmail.comsch rieb

I'm trying to use the DateDiff function to calculate the difference
whether a shift has been setup. when i run the code below with
strFirstShiftEn d as a stringor date or datetime. I get an error
Argument Date1 cannot be converted to type Date. an anyone clear
this up.

If DateDiff("n", Format(Now, "hh:mm AMPM"), Format(strFirst ShiftEnd,
"hh:mm AMPM")) <= 0 Then
* * * * * *'logout
* * * * * *MsgBox("A shift change has occurred. You will be logged
out now.")
* * * *End If

Never use Strings to try to calculate with. Use the Date and TimeSpan data
types to store these values. Convert to/from String only if needed, e.g. for
visual display/input or file I/O.

An example:

* * * Dim d1, d2 As Date
* * * Dim ts As TimeSpan

* * * d1 = Date.Parse(Inpu tBox("enter a date"))
* * * d2 = Now
* * * ts = d1.Subtract(d2)

* * * MsgBox("Differe nce is: " & ts.TotalMinutes & " minutes")

So,
- Date (actually DateTime) stores any point in time (which does not have a
duration).
- TimeSpan stores the, surprise, time span between two points in time. You
can get the duration in any unit you want by accessing the Timespan's
members.

Armin

Armin the short of it is this......i have a number of number up down
boxes that users will enter the hour in one box and the minute in the
other box and in a combo box select the choices AM or PM.....How can i
get those values into the above solution u gave me.

Merry Christmas

[Armin Zingler]

"cmdolcet69 " <co************ @hotmail.comsch rieb

Dim d1, d2 As Date
Dim ts As TimeSpan

d1 = Date.Parse(Inpu tBox("enter a date"))
d2 = Now
ts = d1.Subtract(d2)

MsgBox("Differe nce is: " & ts.TotalMinutes & " minutes")

So,
- Date (actually DateTime) stores any point in time (which does
not have a duration).
- TimeSpan stores the, surprise, time span between two points in
time. You can get the duration in any unit you want by accessing
the Timespan's members.

Armin

Armin the short of it is this......i have a number of number up down
boxes that users will enter the hour in one box and the minute in
the other box and in a combo box select the choices AM or PM.....How
can i get those values into the above solution u gave me.

I don't know because above you are using "Now" which also contains the date.
Now it seems you only want to subtract times.

Reduced to the scenario you gave in the last paragraph, I would do it this
way:

Dim ts As TimeSpan
Dim hours, minutes As Integer

hours = CInt(Me.Numeric UpDown1.Value)
minutes = CInt(Me.Numeric UpDown2.Value)

If Me.ComboBox1.Se lectedIndex = 1 Then
hours += 12
End If

ts = New TimeSpan(hours, minutes, 0)

Then you can work with the Timespan objects.

But, I'm not sure how you want to handle the date part.

Merry Christmas

Merry Christmas

Armin

[cmdolcet69]

On Dec 26, 12:34*am, "Armin Zingler" <az.nos...@free net.dewrote:

"cmdolcet69 " <colin_dolce... @hotmail.comsch rieb

Dim d1, d2 As Date
Dim ts As TimeSpan

d1 = Date.Parse(Inpu tBox("enter a date"))
d2 = Now
ts = d1.Subtract(d2)

MsgBox("Differe nce is: " & ts.TotalMinutes & " minutes")

So,
- Date (actually DateTime) stores any point in time (which does
not have a duration).
- TimeSpan stores the, surprise, time span between two points in
time. You can get the duration in any unit you want by accessing
the Timespan's members.

Armin

Armin the short of it is this......i have a number of number up down
boxes that users will enter the hour in one box and the minute in
the other box and in a combo box select the choices AM or PM.....How
can i get those values into the above solution u gave me.

I don't know because above you are using "Now" which also contains the date.
Now it seems you only want to subtract times.

Reduced to the scenario you gave in the last paragraph, I would do it this
way:

* * * Dim ts As TimeSpan
* * * Dim hours, minutes As Integer

* * * hours = CInt(Me.Numeric UpDown1.Value)
* * * minutes = CInt(Me.Numeric UpDown2.Value)

* * * If Me.ComboBox1.Se lectedIndex = 1 Then
* * * * *hours += 12
* * * End If

* * * ts = New TimeSpan(hours, minutes, 0)

Then you can work with the Timespan objects.

But, I'm not sure how you want to handle the date part.

Merry Christmas

Merry Christmas

Armin- Hide quoted text -

- Show quoted text -

The reason i was using the .now function was because i need to compare
the shift changes from the actual time. Do you think i can still do
this?

[Armin Zingler]

"cmdolcet69 " <co************ @hotmail.comsch rieb

Then you can work with the Timespan objects.

But, I'm not sure how you want to handle the date part.

Merry Christmas

Merry Christmas

Armin- Hide quoted text -

- Show quoted text -

The reason i was using the .now function was because i need to
compare the shift changes from the actual time. Do you think i can
still do
this?

Again I'm not sure. Do you want to subtract DateTime values or Timespan
values? Please give me a specific example (or some) which values you have
(Dates, times, whatever) and where you get them from. What is a "shift
change"?
Please explain it.
Armin

[cmdolcet69]

On Dec 27, 5:07*am, "Armin Zingler" <az.nos...@free net.dewrote:

"cmdolcet69 " <colin_dolce... @hotmail.comsch rieb

Then you can work with the Timespan objects.

But, I'm not sure how you want to handle the date part.

Merry Christmas

Merry Christmas

Armin- Hide quoted text -

- Show quoted text -

The reason i was using the .now function was because i need to
compare the shift changes from the actual time. Do you think i can
still do
this?

Again I'm not sure. Do you want to subtract DateTime values or Timespan
values? Please give me a specific example (or some) which values you have
(Dates, times, whatever) and where you get them from. What is a "shift
change"?
Please explain it.

Armin- Hide quoted text -

- Show quoted text -

Well what it all boils down to is this: a user will setup his shift
times he got 3 choices (1st shift, second shift, and third shift)
which he enters this information from a updown boxes. once set when he
taking data i need to have a timer that will compare the actual date
versus the shift time. If the shift time is older then the actual time
then it will log the user out...... I thhink i would need to have a
timer that would be triggered when the user first opens the
program....howe ver how can i compare the actual time to the shift time
and if the shift time is older then the actual time then it will log
the user out.

[Armin Zingler]

"cmdolcet69 " <co************ @hotmail.comsch rieb

>
Sorry i may be a little confused. What i want to do is have a user
put in a time span value.
combobox1= 6 combobox 2 = 30 combobox3=AM
combobox4=11 combobox5= 30 combobox6=AM

I want to take those values all in the combobox and compare then to
the actual time.

How can i do that?

My previous example

Dim ts As TimeSpan
Dim hours, minutes As Integer

hours = CInt(Me.Numeric UpDown1.Value)
minutes = CInt(Me.Numeric UpDown2.Value)

If Me.ComboBox1.Se lectedIndex = 1 Then
hours += 12
End If

ts = New TimeSpan(hours, minutes, 0)

was using NumericUpDown controls, but you can replace it by comboboxes, too.
Use the SelectedIndex instead to determine the hours/minutes. It shows how
to get the time from the UI into a TimeSpan variable. To get the current
time, call DateTime.Now.Ti meOfDay. To compare TimeSpan values in VB 2003
(which you are using IIRC), compare their Ticks property (TS1.ticks <
TS2.ticks), otherwise use the < operators.
Armin