CalVer Users

Calendar versioning has a long history, and CalVer users can be found in all areas. This ever-growing, never-complete list of project names and example versions is open to expansion.


For more details about the notation and for more detailed use cases, see the CalVer overview.


From small to large, closed and open, many systems and applications from incorporating calendar dates into their projects.

Project CalVer Format Examples
Ubuntu YY.0M 4.10 - 20.04
NixOS YY.0M 13.10 - 17.03
Microsoft Windows YY/YYYY 95, 98, 2000
OpenSCAD YYYY.0M 2015.03
JetBrains PyCharm YYYY.MINOR.MICRO 2017.1.2
ArchLinux YYYY.0M.0D 2018.03.01
Unity YYYY.MINOR.MICRO 2019.2.2
Slack for Mobile YY.0M.MICRO 19.08.10
CockroachDB YY.MINOR.MICRO 19.1.0
Dgraph YY.0M.MICRO 20.03.0, 20.03.1-beta.Jun15
Spring Cloud YYYY.MINOR.MICRO 2020.0.0-RC2
Tesla Firmware YYYY.WW.MICRO 2020.12.10
KDE Apps YY.0M.MICRO 20.12.0
Consensys Quorum YY.MM.MICRO 20.10.0
Home Assistant YYYY.MM.MICRO 20.12.1


Programming language standards are conventionally named for their year (YY/YYYY), and comprise some of the oldest notable usages of calendar versioning.

Project CalVer Format Examples
Ada YY/YYYY 83, 95, 2012
ALGOL YY 58, 60, 68
C YY 89, 99, 11
C++ YY 98, 03, 11, 14, 17
Fortran YY/YYYY 66, 77, 90, 95, 2003, 2008
ECMAScript (aka JavaScript) YYYY 2015, 2020
Python manylinux YYYY 2010 ("backwards compatible to")


CalVer software libraries allow developers to evaluate their software freshness with just a glance at the dependency list.

Project CalVer Format Examples
Boltons YY.MINOR.MICRO 17.2.0
Twisted YY.MM.MICRO 16.1.1
certifi YYYY.MM.DD 2016.2.28
pytz YYYY.MM 2016.4
attrs YY.MINOR.MICRO 17.4.0
pip YY.MINOR.MICRO 18.0 - 19.0.3


System administrators appreciate a tool with a proper version.

Project CalVer Format Examples
pip (details) YY.MINOR.MICRO 19.2.3
youtube_dl YYYY.0M.0D.MICRO 2016.06.19.1
fusefs-ntfs YYYY.MM.DD_MICRO 2016.2.22_1
black YY.MM.MICRO 18.3a0


If you know of a CalVer usage that does not fit into these categories, please submit it here.