One way would be to start your job Wednesdays at 22:10:00.
- First task call a powershell script that generates a random number between 0 and 9 inclusive, then waits for than many minutes.
Then proceed with the next task.
Here's the simple powershell script:
#
# Wait for a random number of minutes between 0 and 9
#
Start-Sleep -s ((Get-Random -Maximum 10)*60)