This plugin provides the build start timestamp as a parameter, which is great
The timestamp format isn’t easily configurable
Installation is again non-standard
The plugin notes say it’s a bit of a memory hog, and it was meant as a demo anyway
So I just wrote my own.
Formatted Date Parameter provides a confguration parameter (named build.formatted.timestamp), which during build will contain the build start timestamp. The timestamp format is ISO-1806 by default (“yyyy-MM-dd’T’HH:mmZ”). The timestamp format can be configured using another configuration parameter (named build.timestamp.format), which uses standard SimpleDateFormat syntax.