i have issue with floating point rounding in javascript. As far as i know number in javascript are IEEE-754 floating point under the hood (no option about that), so not all integer value are allowed due to rounding.

For example the following code will produce this value as output -> "637889210422071800" instead of "637889210422071841" as one should expect

document.writeln(parseFloat("637889210422071841"));
document.writeln("<br>");
document.writeln(parseInt("637889210422071841",10));

Problem is that this number (basically a clock) is served in a rest api response, but when i try read the resposne i get the wrong value (probably due to some implicit deserialization over javascript object). Luckily i have control over the rest api, so i can change how the clock is encoded.

So first option come to my mind is to change the clock format and make it a string, so that i can read the real value from javascript (i have still to interpret it, but at least the value is preserved, so this solution is a bit tricky and is not my first choiche). Another option i think about is to decrease the size of my clock, reducing it's sensibility, basically instead of use "6378892104220718|41" i will truncate it to "6378892104220718". I prefer the second option, but i am concerned about the fact that maybe the rounding error are not uniformly distributed (due to base-exponent structure of IEEE-754 numbers).

So i would like to ask which if there is a way to handle situation like that in javascript, and if there is not a best practice, i would like to ask if reduced clock version will solve my issue.