# Re: st: decimal years

 From "Austin Nichols" To statalist@hsphsun2.harvard.edu Subject Re: st: decimal years Date Fri, 11 Aug 2006 15:54:44 -0400

```Nick--
There was an unfortunate accidental deletion in the middle of my last
post, esp. since the two sentences joined parse as one.  I insert the
missing text below:

On 8/11/06, Austin Nichols <austinnichols@gmail.com> wrote:
```
```Nick--
Yes, I was joking about year zero, but decimal-year dates -0.1 and
-4.1 would be in 1 and 5 BCE, respectively, right?  So I was right to
use -g y=floor(ev)- for the year calculation, I think.  The trouble
```
```arises in calculating the days elapsed since 1960 came around, which
means calculating the years elapsed (backwards) across an imaginary
zero year of length 365 (if that makes any sense).  A further problem

```
```arises with the days in the year, which would be a fraction (1-x) from
the start of the year, where x is the fractional part of the date
variable.  Though given that the seventh month was named after a guy
who died in 44 BCE and the eighth month was named after a guy who died
in 14 AD, I don't know that you'd really want to use the date format
there.  Why doesn't Stata have the Gregorian-Julian-Israeli-etc.
calendar conversion built in, anyway?

```
```ps.
Note that Stata stops caring at 100 AD:

. di %d -679350
01jan0100

. di %d -679351
-6.79e+05
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```