1. A method of automating patching of a computer system, the method comprising: determining, by a local computer remote from the computer system, whether a computer patch is available for a computer system of a customer; determining, by the local computer, a patch management policy of the customer; retrieving, by the local computer, a computer file from the computer system including a category representing a purpose for which the computer system is used; searching, by the local computer, for an entry in a table associated with the customer that lists a plurality of different categories and corresponding patch offset times; setting, by the local computer, a patch offset time to the listed patch offset time whose category matches the category in the retrieved file; determining, by the local computer, a patch window of the customer based on the determined patch management policy and the patch offset time; and directing, by the local computer, application of the computer patch to the computer system at the determined patch window.