The 50 days is arbitrary - the owners of GetTickTime should have written tests to handle what happens when the tick value rolls over. (Maybe they did, and allow

The 50 days is arbitrary - the owners of GetTickTime should have written tests to handle what happens when the tick value rolls over. (Maybe they did, and allowing it to roll over was the desired behavior.) But more to the point - the consumers of GetTickTime should have also had tests to verify that the consuming code appropriately handles time rollovers. Granted, this was Win95 so I'll cut them some slack, but that should be standard procedure for any code that consumes an incrementing counter API. First question should always be - 'how will this code handle a rollover value'?