J.P.'s Blog

At whatever time that I was at on June 8th, 2009 (I don’t exactly know the time, so your going just have to assume that I speak of whenever that is), it will have been 946771216000 milliseconds (UTC) since I was actually born. …or will it…?

The strange part is just how hard it is to actually answer that question. You may ask why I chose milliseconds (ok, by now actually some of you may not ask anymore and may just assume as much from me), but in the end it served a purpose. You see, I was reading up on leap seconds for my calculations (there were 16 added since I was born). As such, I was able to calculate that since June 8th, 1979, there were:

      2928 days from leap years
+    8030 days from non-leap years
=  10958 days

   945388800 seconds from non leap days
+     1382416 seconds from 16 leap days

= 946771216 seconds (UTC)

However, a Mean Solar Day is actually 86400.002 seconds. This means that more precisely, it has been:

946771237916 milliseconds since June 8th, 1979 (Which I believe is UT1 actually)

or: ((10942 days * 86400.002s) + (16 days * 86401.002s))

However additionally, each solar day is actually getting longer by about 1.4ms to 1.7ms per century (depending on which wikipedia post you read). So with THIS new data, the numbers are more like:

946771243504.58 milliseconds since June 8th, 1979 (accounting for tidal shifts)

or ((10942 days * 86400002.51 ms) + (16 days * 86401002.51 ms))

So if you really care, there is a ton of data out there on various types of precision. The REAL problem came because UTC defines a second, SI defines a day, and years (or annums) are defined differently as well.

You know the real sad part to all this though? Neither google, bing, nor Wolfram Alpha gave the correct result.

Google: 30 years = 946 707 779 241 milliseconds

Bing: 30 years = 946,707,779,808 milliseconds

Wolfram Alpha: 30 years = 9.461x10^11 ms

At first I thought maybe its just rounding differences, but all three are completely different and none are close to what I calculated (which I triple checked over the last hour… in fact this was supposed to be ready before midnight). Oh well.

In the mean time (17 mins ago) I turned thirty.

J.P.