It converts between Chinese and Gregorian and viceversa.
Many other features can be found in the docs.

Readme created with ARC 3.1 - Copyright (c)1996-98 by Jens Weyer.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]                11155   19084  58.5% -lh5- c5ec Mar 15  1999 Lunar/lunar
[generic]                  313     632  49.5% -lh5- 145b Mar 15  1999 Lunar/lunar.amiga
[generic]                 1372    2777  49.4% -lh5- 9902 Jun 21  1991 Lunar/Original/lunar.1
[generic]                  452    1731  26.1% -lh5- 737b Jun 21  1991 Lunar/Original/lunar.bitmap
[generic]                 7847   23460  33.4% -lh5- 4da5 Jun 21  1991 Lunar/Original/lunar.c
[generic]                   89      98  90.8% -lh5- e65f Jun 21  1991 Lunar/Original/Makefile
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         6 files   21228   47782  44.4%            Mar 21  1999