vb6 Compare times in list with current time - time

Question

I'm making form where i need to enter the time's for each period like.
Start time - End time
Start time - End time
Start time - End time
Those record's could be saved in listbox as in my example. On another form i have 3 labels
CurrentTime, TimePassed, TimeLeft, and a Timer which ticks in interval 1second. So the time in timepassed ticking up, time left ticking down, and current time show correct time while application is opened.
In final it looks like this
Private Sub cmdAdd_Click()
Call addp
End Sub
Function addp(Optional ByVal t As String)
Dim s As String, e As String
If t = "" Then s = Trim(InputBox("Start time (hh:mm AM/PM):")) Else: s = Trim(Split(t, "-")(0))
If s = "" Or InStr(1, s, " AM") = 0 And InStr(1, s, " PM") = 0 Then Exit Function
If chk(s) = False Then Exit Function
If t = "" Then e = Trim(InputBox(s & "-?" & vbCrLf & "End time:")) Else: e = Trim(Split(t, "-")(1))
If e = "" Or InStr(1, e, " AM") = 0 And InStr(1, e, " PM") = 0 Then Exit Function
If e = s Then Exit Function
If chk(e) = False Then Exit Function
If Format$(Split(s, "-")(0), "hh:mm AM/PM") > Format$(Split(e, "-")(0), "hh:mm AM/PM") Then Exit Function
If lstPeriods.List(0) <> "" Then
If Format$(Split(lstPeriods.List(lstPeriods.ListCount - 1), "-")(1), "hh:mm AM/PM") > Format$(Split(s, "-")(0), "hh:mm AM/PM") Then Exit Function
End If
lstPeriods.AddItem lstPeriods.ListCount + 1 & ". " & s & "-" & e
If frmMain.lblPeriod.Caption = "" Then Call snd(s & "-" & e, lstPeriods.ListCount)
End Function
For check
Function chk(ByVal st As String) As Boolean
st = Replace$(Replace$(st, " AM", ""), " PM", "")
If UBound(Split(st, ":")) <> 1 Then Exit Function
For i = 0 To 1
If IsNumeric(Split(st, ":")(i)) = False Then Exit Function
If Len(Split(st, ":")(i)) <> 2 Then Exit Function
If Split(st, ":")(i) < 0 Then Exit Function
Next
If Split(st, ":")(0) > 12 Then Exit Function
If Split(st, ":")(1) > 59 Then Exit Function
chk = True
End Function
The solution i gave is the only solution which beginner as i I had. And i know it's confusing and very slow. There is no way this can be finished by using trim/split/format because it require for a lot of modification.
Searching for easier solution.
Sp i need to compare the current time on computer with the time person enetered in textbox/listbox how can i do that .

Answer 1

To Run this code you need to add 5 Controls to the Form1
lblSystemTime = Label Control
lblTimeLeft = Label Control
lblTimePassed = Label Control
lblPeriod = Label Control
tmrSystemTime = Timer Control
Dim Periods()
Private Sub Form_Load()
Periods = Array( _
"06:00 PM-07:00PM", _
"07:01 PM-08:00PM", _
"09:00 PM-10:00PM", _
"1AM-2AM" _
)
End Sub
Private Sub tmrSystemTime_Timer()
lblSystemTime.Caption = FormatDateTime(Now, vbLongTime)
Dim OnPeriod As Integer
OnPeriod = GetPeriod()
If OnPeriod < 0 Then
lblTimeLeft.Caption = vbNullString
lblTimePassed.Caption = vbNullString
lblPeriod.Caption = "Unknown Period"
Else
lblPeriod = CStr(OnPeriod + 1) & ". period"
lblTimeLeft.Caption = "Time Left: " & Format( _
DateAdd("s", _
DateDiff("s", _
CDate(lblSystemTime.Caption), _
CDate(Split(Periods(OnPeriod), "-")(1))), _
CDate("0") _
), _
"nn:ss" _
)
lblTimePassed.Caption = "Time Passed: " & Format( _
DateAdd("s", _
DateDiff("s", _
CDate(Split(Periods(OnPeriod), "-")(1)), _
CDate(lblSystemTime.Caption)), _
CDate("0") _
), _
"nn:ss" _
)
End If
End Sub
Private Function GetPeriod() As Integer
Dim ICount As Integer
For Each Pr In Periods
If CDate(Split(Pr, "-")(0)) <= CDate(lblSystemTime.Caption) And _
CDate(Split(Pr, "-")(1)) >= CDate(lblSystemTime.Caption) Then
GetPeriod = ICount
Exit Function
End If
ICount = ICount + 1
Next
GetPeriod = -1
End Function

Answer 2

Here is something which may help:
Private Sub TimeCheck(byval int_TimeNow as Integer)
dim intTimeThen as string 'set a variable to compare for the THEN time
dim intTimeNow as string 'set a variable to compare for the NOW time
dim intDiff as string ' set a variable for the difference in time
intTimeNow = int_TimeNow 'just to ensure we don't mess with any data
intTimeThen = val(txtTimeThen.text) 'get the numeric value of the time, the system will
'convert it from a string to the value here.
intDiff = intTimeThen - intTimeNow 'Do the math
lstTimeEvents.additem timevalue(intDiff) 'write it to a listbox
End Sub
I realize this is not the coding convention you are using, but it should demonstrate what you are looking for to some degree.