Once again today, in a center near me, service was thrown under the bus disguised as weather issues in regards to Next Day Air commit times. As it was explained to me, we were delayed this morning due to the arrival of many ground packages that had been delayed due to the winter storms in the Great Lakes area last week. The preload was about 45 mins late wrapping up. Before I made my first stop we received an OMS message instructing us to sheet any late air as "weather". Upon my return this evening, I asked my center manager how we could do this in clear conscience since there was no bad weather here last night? His answer was that the packages that caused our late departure was due to bad weather elsewhere last week. When I asked him what that had to do with the customers that contracted our premium next day service yesterday with the expectation of their package being delivered by 10:30am this morning? His answer was..........silence. This company is systematically losing all integrity and in the process it's very soul. P.S. I delivered all of my Next Day Airs on time. Had i not, I most certainly would not have followed instructions.