Sky Calendar - download

Download the installation file:
Operating system Program version File Name Size
Windows Windows 8, 8.1 or 10 - 32 bit 4.8 nk4a.exe 9,30 MB Download
Windows Windows 8, 8.1 or 10 - 64 bit 4.8 nk4b.exe 10,40 MB Download
Apple MacOS (OS X) 10.9 and higher 4.8 NK4Mac.zip 12,50 MB Download

Program installation:
  • Windows: Run the downloaded file and follow the instructions of the installer. If you experience problems, check out the page FAQ.
  • Mac: Be sure to read the Recommended Installation Procedure!
The program manual
is part of the installation, but you can also download it separately (1,6 MB).



Alternatively, you can download the program just as a ZIP file to save Sky Calendar without installation (Windows only):
Operating system Program version File Name Size
Windows Windows 8, 8.1 or 10 - 32 bit 4.8 nk4a.zip 11,70 MB Download
Windows Windows 8, 8.1 or 10 - 64 bit 4.8 nk4b .zip 13,60 MB Download

Save and run program:
Download the program, unpack it to any empty folder and run NK4.exe.


Unregistered version restrictions:
  • All work can be done only for period of 2000 to 2030 years (for 1 to 3000 years in registered version).
  • There are no other restrictions in unregistered version of Sky Calendar!