'Call this function to check whether the values for the hours, minutes and seconds are met
Public Function Alarm(hours As Variant, minutes As Variant, seconds As Variant)

'Set Alarm to 1 to start with
Alarm = 1

'Check if hours is null - if not, check whether it matches the actual time
If hours <> "" And Hour(Time) <> hours Then Alarm = 0 'If it doesn't then set Alarm to 0 - the alarm should not sound
'Check if minutes is null - if not, check whether it matches the actual time
If minutes <> "" And Minute(Time) <> minutes Then Alarm = 0 'If it doesn't then set Alarm to 0 - the alarm should not sound
'Check if seconds is null - if not, check whether it matches the actual time
If seconds <> "" And Second(Time) <> seconds Then Alarm = 0 'If it doesn't then set Alarm to 0 - the alarm should not sound

'Finished Checking
End Function

'Example of Calling Function
'Call in timer to keep checking to see if alarm should go off
Private Sub Timer1_Timer()

'Error Trap
On Error GoTo errtrap

'Set the values that will be checked
'(Integer them to block errors and convert string values to numbers)

hours = Int(Text1.Text)
minutes = Int(Text2.Text)
seconds = Int(Text3.Text)

'Call Function with the parameters as the values to check for
Value = Alarm(hours, minutes, seconds)

'If a Value of 1 is return then the requirements are met
If Value = 1 Then MsgBox "Alarm!"

GoTo Done 'Finished

errtrap:

'Trap checks to see that all the testing values (hours, minutes and seconds) are not null or strings
'i.e. at least 1 value must be testing for
erred = erred + 1

'If erred=3 then all values are null, so do not check for alarm
If erred = 3 Then GoTo Done

'Otherwise, resume at the next line
Resume Next

Done:
'Finished
End Sub