SSC Rookie..
Try this out-
declare @string nvarchar(max)
select @string = '8Am to 6PM Mon-Fri| |Tow: 3PM to 8PM Mon-Fri, 4AM -11PM Fri-Sat| Clean: 9AM to 11PM Mon-Fri, 4AM -7AM Fri-Sat| '
select substring(@string,patindex('%Tow:%',@string),patindex('%Clean:%',substring(@string,patindex('%Tow:%',@string),len(@string)))-3)
-J