npm version number for SaaS application

I am working on a SaaS application with node.js using npm for managing dependencies. I am trying to decide what to do about the version number. Our release model will be to market features and release when ready, rather than marketing versions.

I am looking for advice on the version field for package.json. Since we won't be publishing the app to the npm registry, I can really use whatever version number I want. I really don't want to maintain a typical version number like 1.0, 1.2, 2.0, etc. Since a release is simply a project that ships when ready, dates make better versions for me, like "RELEASE_20130104", but npm requires that the version field in package.json be parseable by semver rules.

I am interested in hearing what the rest of the community has done for SaaS npm-based apps.

Requirements:

  1. Effortless - I don't want to waste time debating between 1.2.0 or 2.0. It's just the next release.
  2. Must satisfy the npm version syntax rules.

Nice-to-haves:

  1. Scriptable through a build process, like extracting SVN branch and revision number.
  2. Version means something, like the release date.

Solutions I have come up with:

  1. Strictly follow semver major.minor.patch pattern. This will require separate scripts for different release types and will be a nightmare for pre-release builds.
  2. Express the release date in semver format like "2013.01.04"
  3. SVN revision number + branch or tag name like "21484-BugFix21". Downside there is that non-release builds' versions don't tell you what release version they are branched from.
  4. Pick a dummy version and never change it like "1.0.0". Track the version in the format I want in a separate field, like "appRelease": "2013.01.04".

I don't expect right or wrong answers. There are a ton of solutions. I am looking to see what approaches others have taken in the past.