You laughed laughed and laughed...you mask fell off...when somebody is presented with the moment of truth ..they laugh and laugh and laugh like you do..
You dont seem to understand simple things..your Q? was how could Feb be in 3000 bc when the roman calendar was found in 700AD ..looks like you dont seem to get simple things..any calendar system can be applied to any other calendar system provided they follow a cyclic pattern..so of somebody finds a calendar 4000 years from now..hindu as well as roman calendars can be applied to it to get relevant dates
Ramayan has references to several of these celestail events and hence it possibe to calculate dates accurately.
Looks like you dont seem to understand simple things and you laugh and laugh..keep laughing..no point in replying to you..