How to use Date in Javascript for prehistoric dates?

Question

I’m working on a project where the JavaScript Date isn\'t big enough.

I want to place multiple events on the same time axis, some of them have month and day and some don

Answer 1

The ECMAScript says:

A Date object contains a Number indicating a particular instant in time to within a millisecond. Such a Number is called a time value. A time value may also be NaN, indicating that the Date object does not represent a specific instant of time.

Time is measured in ECMAScript in milliseconds since 01 January, 1970 UTC. In time values leap seconds are ignored. It is assumed that there are exactly 86,400,000 milliseconds per day. ECMAScript Number values can represent all integers from –9,007,199,254,740,992 to 9,007,199,254,740,992; this range suffices to measure times to millisecond precision for any instant that is within approximately 285,616 years, either forward or backward, from 01 January, 1970 UTC.

The actual range of times supported by ECMAScript Date objects is slightly smaller: exactly –100,000,000 days to 100,000,000 days measured relative to midnight at the beginning of 01 January, 1970 UTC. This gives a range of 8,640,000,000,000,000 milliseconds to either side of 01 January, 1970 UTC.

The exact moment of midnight at the beginning of 01 January, 1970 UTC is represented by the value +0.

So you can create a custom method for Dates where you can use the integer value as the year. But on a practical note Ecmascript range for dates is good enough to hold all the practical dates. The one which you are trying to achieve does not make a real practical sense/meaning as even one is not sure if it follows the Babylonian astrology?