A little thought is needed here !
You live in Italy, you have an ephemeris calculated for Noon-GMT positions, you print calendars.
You live in California, you have an also have an ephemeris, its calculated for Midnight-GMT position, and you also print calendars.
So two calendars hit the market. A lady in Maine buys one. She loses it and buys another, different calendar. She finds the first one. One says the Sun will move into a sign on a given date. The other says the Sun will move into that next sign on the following date. Which is right? Both of them! Which one will you use? Who cares. Unless you have a need or accuracy or have a birthday on one of those two days, your life won't change much on such a trivial point. If you need the accuracy you'll get ahold of some software or a local almanac with a good reputation and go with what it tells you.
There are many good reasons why two sources can offer contradictory information. Those reasons typically involve issues of calculation accuracy, the type of calculation system used (tables, computers, ephemerides, etc.), the source of basic data (there are several institutions that calculate astronomical data including the US Naval Observatory, the Jet Propulsion Lab, Greenwich Observatory, a swiss firm whose name escapes me, and several more). Add to that all of the various astronomical and astrological software packages that use various sources and have their own calculation routines, and you have more variables than Carter has little liver pills. Add to that all of the confusing time zones and local exceptions -- well, there are a number of paths to in-accuracy.
If you can easily assimilate these broad ideas, then you should not be bothered by two sources of generalized data. Dave.