Fundamentally, momentum conservation is linked to invariance under space translations. See Noether's theorem. If you want to find a system that does not conserve momentum you should look for situations where space is not uniform, e.g. balls rolling on the surface of a bowl, a planetary system (when the dynamics of the sun is neglected), etc.
Socorro is a city in Socorro County in the U.S. state of New Mexico. It is in the Rio Grande Valley at an elevation of 4,579 feet (1,396 m). In 2012 the population was 8,906.
Over the course of April in Socorro, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 58 minutes, implying an average daily increase of 1 minute, 59 seconds, and weekly increase of 13 minutes, 56 seconds.