Meanings of 'since' and 'to'

Looking at the web_api documentation in 8.6.0, I see the api/qualityprofiles/changelog function has parameters ‘since’ and ‘to’. From experimentation it appears that ‘since’ means ‘on or after’ while ‘to’ means ‘strictly before’ – i.e., “since=T1; to=T2” means any time T such that T1<=T<T2.

Would be nice for this to be in the documentation. Currently it looks like this:

For instance, the documentation for api/project_analyses/search makes this clear for the ‘to’ parameter: