Hi Paul, I think it would be possible for me to do some minor change to allow seconds in UNIX time as a start time. I try to send a new patch later. Regarding the end time, we currently don't have a use case for it and it will requires a bigger effort. However, the changes I have made will be a base for further development of the time truncation functionality mentioned in RFC 8536. BR, Christopher Wong ________________________________________ From: Paul Eggert <eggert@cs.ucla.edu> Sent: Tuesday, March 5, 2019 20:43 To: Christopher Wong Cc: Time Zone Mailing List Subject: Re: [tz] [PROPOSED] zic option for including data from a certain year onward Thanks for the suggestion. It'd be helpful to have a truncation option for zic. However, the option should allow the user to select an arbitrary contiguous region of time: that is, not necessarily at year boundaries, and perhaps including an end time as well as a start time. This would be useful for people trying to implement the time truncation feature of Internet RFC 8536.