INSTALL

Like any other piece of software (and information generally), libtai
comes with NO WARRANTY.


These are UNIX installation instructions; libtai has not yet been ported
to non-UNIX systems.


To compile the programs and format the man pages:

   % make

Then, as root, enable leap second support:

   # cp leapsecs.dat /etc/leapsecs.dat
   # chmod 644 /etc/leapsecs.dat

To use another compiler, edit conf-cc and conf-ld.


There are five test programs here. The first is leapsecs, which creates
leapsecs.dat from leapsecs.txt. Try

   % ./leapsecs < leapsecs.txt | cmp - leapsecs.dat

to make sure that there are no differences.

The second is check, which prints a variety of information about an
ISO-style input date. Try

   % ./check < check.in | cmp - check.out

to make sure that your test results match mine. Note that the results
for future dates will change when more leap seconds are announced.

The third is easter, which prints the date of Easter in any given year.
Try

   % ./easter 1997 1998 1999 2000 2001

and check the results against tables from some other source.

The fourth is yearcal, which prints a year-long calendar. Try

   % ./yearcal 1997 | ul

and check the results against another calendar. (The days in January,
March, May, July, September, and November should show up in boldface.)

The fifth is nowutc, which prints the current time in UTC. Your system's
clock must be the number of seconds since 1970-01-01 00:00:10 TAI. This
is compatible with the interpretation of time_t in the Olson time
library with leap seconds enabled. Try

   % env TZ=right/Etc/GMT date; ./nowutc

if your system has the Olson library.


The libtai code is in the public domain, so you can use it in your own
programs. But keep in mind that this is a very early release. Some of
the code hasn't been tested at all! caldate_mjd() and caldate_frommjd()
are based on previous code of mine; they need outside review. It would
be particularly helpful to systematically check my results against
independent results from someone else's code.