cl-libtai is an implementation of TAI, the international time standard Temps Atomique International, under the LGPL license.

For details on how TAI relates to UTC and Unix Time, see the utctai page. The original public domain C library with plenty of documentation is accessible here

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This project has released a cl-libtai.tar.gz asdf loadable package

Related Links


You can browse our CVS repository or download the current development tree via anonymous cvs, as described here


A subversion directory is available at For windows platforms, consider using the Tortois SVN client to navigate.

Testing and getting started

After successfully loading the cl-libtai package with asdf, you're ready to try some of the libtai commands.

For example: (caltime-utc (tai-now)) to show the current time in year, month, day format.

There is a test-libtai.lisp in the source repositories that demonstrates how to transform among the various tai, caldate, and caltime structures. See also the application and tutorial example for details on how you might use cl-libtai in your own program.

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