You are proving my point. When talking light travel you should NOT ADD time for those not traveling, you should subtract time from those traveling: ergo: a 4 light year flight will appear to take less time for the traveler, but it still takes 4 years for everyone else. The EXACT OPPOSITE of what people say and even their examples for proving their point proves mine.
Maybe I did not make the point clear, but no one is adding or subtracting time. The passage of time is relative for each person
The round tip takes a month for a traveller.
For someone on earth years may have passed. The traveller experienced a month, the person left on earth experienced years
The net effect being that the traveller seemed to have travelled into the future compared to the person who remained on earth the whole time