timever, time based versioning

README.md

timever

time-ver

Time based versioning

Synopsis

For versioning published releases of websites/services, we use a datetime based string to denote different releases

DATE.TIME.SUBTIME

• DATE, a YYYYMMDD formatted value
  • YYYY is a 4 digit year (e.g. 2015)
  • MM is a 2 digit month (e.g. 06)
  • DD is a 2 digit day (e.g. 08)
• TIME, a HHMMSS formatted value
  • HH is a 2 digit hour (e.g. 08)
  • MM is a 2 digit minute (e.g. 25)
  • SS is a 2 digit second (e.g. 22)
• SUBTIME, a N formatted value
  • N is a 9 digit nanosecond (e.g. 039235885)

// TODO: Maybe use date % notation instead?

Example:

20150608.082522.039235885

Generating on GNU/Linux:

date --utc +%Y%m%d.%H%M%S.%N

Why

When we began automating our release process for websites/services, we found there was no well formed solution to identifying what release is live.

• semver doesn't play nice with automation, usually minor or patch is bumped without any consideration
  • Introducing actual semver releases into automated releases is possible but doesn't gain any value from a maintainer's perspective
• Using revisions from git works but makes it hard for human's to refer to reference and has no intrinsic value

We solved this by using time; a very practical value from a human's perspective. From a given version, we know when it was created and can reuse that reference during the publication process.

Other benefits include:

• Compatible with semver libraries (although, x and * lose meaning quickly)
• Lexically sortable

Usage

We like to use our versioning in:

• git tag at publication (e.g. creating/pushing a new release)
• Folder/archive name for release (e.g. stored on server with archive for easy debugging of live version)

Alternative names:

• timestamp ver
• datetime ver
• dt ver

OS X doesn't support the %N notation. As a result, we need to install coreutils which makes it gdate. Maybe we can document that as well as other language alternatives (e.g. python):

$ python -c "import datetime; print(datetime.datetime.utcnow().strftime('%Y%m%d.%H%M%S.%f000'))"
20150821.052303.269441000

Probably subconscious influence via Package Control

node flavor:

$ node --eval 'console.log((new Date()).toISOString().replace(/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}).(\d{3})Z$/, "$1$2$3.$4$5$6.$7000000"))'
20150821.053452.369000000

ruby flavor:

$ ruby -e "require 'date'; puts DateTime::now().strftime('%Y%m%d.%H%M%S.%N')"
20150821.004046.688937332

Simplfied ruby flavor (with UTC):

$ ruby -e "puts Time.now.utc.strftime('%Y%m%d.%H%M%S.%N')"

http://stackoverflow.com/questions/755669/how-do-i-convert-datetime-now-to-utc-in-ruby

Updated Node.js version:

$ node --print "new Date().toISOString().replace(/[-:Z]/g, '').replace('T', '.') + '000000'"
20180207.224159.441000000

There is process.hrtime() support for nanoseconds but it would require right padding with zeroes

Java version that works in sbt for scala projects

DateTimeFormatter
      .ofPattern("yyyyMMdd.HHmmss.n")
      .withZone(ZoneOffset.UTC)
      .format(Instant.now()),