This is incorrect, Confirming the contentions in the Chronicon, ancient Latin writer Macrobius (Saturnalia, I, XVIII:10) also reported on the annual Egyptian "Christmas" celebration, specifying the time as the winter solstice or "December 25th": 

 …at the winter solstice the sun would seem to be a little child, like that which the Egyptians bring forth from a shrine on an appointed day, since the day is then at its shortest and the god is accordingly shown as a tiny infant. 

 Here we can see the precise meaning of the theme of the newborn sun at the winter solstice, a motif representing the lengthening of days after the darkest time of the year. Egyptologist Dr. Bojana Mojsov explains further the significance in Egypt: "The symbol of the savior-child was the eye of the sun newly born every year at the winter solstice."