The 1st of January is neither Christian nor English. There is absolutely nothing christian about this day nor english about this day.
the 1st of january is the first day in what is called the gregorian calendar. the gregorian calendar is strictly of the romans, by the romans. it did not have the current shape or form since time immemorial. there is a long history behind this calendar which has its origin in what was called 'Julian Calendar'. ever since its origin it has been subjected to numerous amendments and has eventually taken its current structure with last change made being adding 1 day in february every fourth year, which was approved by pope gregory the then pope of rc church from whence it has been populary referred to as gregorian calendar. initially there were only 10 months beginning march. the seventh month was named september after 'septem', the word for the number 7 in latin, which was language in rome then. likewise october after 'octum' for 8, november after 'novum', latin for 9, december after 'decem', latin for 10 (from which decimal system gets its name). when it was discovered that earth takes not 300 but 365 days to complete its revolution around sun, 2 months were inserted in beginning and some months were extended by 1 day making them 31 days. the first month named january after the roman goddess 'janus' who is always worshipped first when performing a ritual, like how pillayar is worshipped by hindus before worshipping any other deity. these are all things taught in english prose class during the seventies. whoever studied school during seventies in tamil nadu matriculation schools could recollect.
england did not have a calendar of its own. after julius ceasar invaded england, the roman catholic church started planting their churches in england. until then the english people do not seem to have had any religious belief. since roman catholic church had its origin in rome, they observed the gregorian calendar. they imposed it on england. the english brought this calendar to india when they imperialized india. hence in india it is being inappropriately referred to as christian calendar or english calendar etc.
since the british ruled almost the whole world once, for the sake of convenience of referring to dates, this gregorian calendar is being used by nations all over the world, after their respective independence.
otherwise there is absolutely nothing new on 1st jan or about this gregorian calendar. this is just another calendar like the thousands of other calendars in the world and 1-jan passes of as just another day like the other days. absolutely no new astronomical event happens on that day to signify that day as beginning of a new year.
celebrating 1-jan as new year is only a sentiment. it is only a relative new year day and there is absolutely nothing absolute about this new year day.
if you are in tamil nadu, celebrating the 1st day of the month of chithirai as new year is most appropriate.
if you in karnataka or andhra, celebrating ugadhi as new year is most appropriate.