How do I change the Time Warning? (ICCforMac/Windows)

Click on the Settings Icon   from the top toolbar > A window opens with a list options on the left. Click on 'Sounds'
Or menu above: Edit > Settings > Sounds
To turn the warning on check 'Enable lowtime Warning'.  Unchecking will turn it off.
You can also set the amount of seconds you want to get a time warning.  Example: 60,10 will give a warning when 60 seconds left (1 minute) and when 10 seconds left.
   
When done click on OK.