The default time zone Leanpub uses is UTC. This will affect e.g. the timing of when coupons expire. Someday we will add a feature so authors can set their time zone, but we can’t promise when. This tool can help you see your time zone in relation to UTC.
The Leanpub team is based on the west coast of Canada, so emails to our support team at firstname.lastname@example.org will usually be responded to during normal working hours PST.