Create an alarm to remind me of my lectures time

Using this code:

In a module :

Option Explicit
Public RunWhen As Double
Public Const cRunIntervalSeconds = 1 ' 10 seconds
Public Const cRunWhat = "The_Sub"  ' the name of the procedure to run


Sub StartTimer()
    RunWhen = Now + TimeSerial(0, 0, cRunIntervalSeconds)
    Application.OnTime EarliestTime:=RunWhen, Procedure:=cRunWhat, Schedule:=True
End Sub
Sub The_Sub()
 [a1] = Now
   ' Call StartTimer to schedule the procedure again
   StartTimer
End Sub

In ThisWorkBook:

Private Sub Workbook_Open()
    The_Sub
End Sub

Originally Posted by Logit

Using this code:

In a module :

Option Explicit
Public RunWhen As Double
Public Const cRunIntervalSeconds = 1 ' 10 seconds
Public Const cRunWhat = "The_Sub"  ' the name of the procedure to run


Sub StartTimer()
    RunWhen = Now + TimeSerial(0, 0, cRunIntervalSeconds)
    Application.OnTime EarliestTime:=RunWhen, Procedure:=cRunWhat, Schedule:=True
End Sub
Sub The_Sub()
 [a1] = Now
   ' Call StartTimer to schedule the procedure again
   StartTimer
End Sub

In ThisWorkBook:

Private Sub Workbook_Open()
    The_Sub
End Sub

Thank you sir for your support.But:
1- as I mentioned before my PC doesn`t have speakers,I want to play the error sound of PC.
2-when I open excel ,I need the code to run(in background and without opening the file) .
3-I want the alert to show up before 20 minutes from due time and then opening the file of lectures to prepare for the lecture.
4-Why did you create a timer??
I don`t need it in my file.You can depend on the time of PC
5-The file doen`t close at all.When I cloe the file ,it reopens again.
Waiting for your feedback

Thank you for your support.But what can I do with this countdown??
I have a tiny knowledge on VBA.
Please help me more

.

1- as I mentioned before my PC doesn`t have speakers,I want to play the error sound of PC.
2-when I open excel ,I need the code to run(in background and without opening the file) .
3-I want the alert to show up before 20 minutes from due time and then opening the file of lectures to prepare for the lecture.
4-Why did you create a timer??
I don`t need it in my file.You can depend on the time of PC
5-The file doen`t close at all.When I cloe the file ,it reopens again.

#1: Someone else will need to provide code for having the system internal speaker emit a sound. Since earphones are in effect "speakers" this syntax should function as desired. I can't explain why it doesn't on your computer as it works fine here.

#2: As far as I know Excel is not capable of 'running in the background' without it being enabled. Suggestion: start the Excel file, minimize it and proceed with your other actions as normal. An alternative would be to
use a program other than Excel.

#3: An easy work around is to enter the times in Column H as twenty minutes prior to your classes.

#4: A timer is required to track the time when the Message Box will become enabled. To not view the time display in Cell A1, you can always change the font color to the cell background color.

#5: Not certain why the file doesn't close on your system. It functions as desired here.

Thank you for the opportunity to provide a free service to you. I learned alot from creating this gratuitous project.

Merry Christmas to you and your loved ones.