Sprig date function consistency across Helm versions

Helm leverages the Sprig library to provide date manipulation functions within chart templates. Because these templates are rendered on the local client or CI/CD runner before being sent to the Kubernetes API, the resulting manifests are static and reflect the environment of the execution machine.

A challenge arises when maintaining charts across diverse environments where different Helm binary versions may bundle different versions of the Sprig library. This can lead to inconsistent timestamp formatting or parsing behaviors when utilizing complex date logic in values.yaml strings.

Technical Constraints

• Lack of a native DateTime type in Helm values.
• Dependency on the local system clock during the rendering phase.
• Variations in Sprig function implementation between Helm releases.

Does the integrated Sprig library maintain strict backward compatibility for date formatting across major Helm versions? What is the recommended approach to ensure deterministic timestamp generation regardless of the client-side Helm version?