When given a UTC date, a Twix iteration is one day shorter than I expect

[barneycarroll]

As seen here.

[barneycarroll]

User error! The confusion is over how UTC affects the moment. According to my confused understanding, by invoking utc, Moment would operate in 'UTC mode', but this isn't the case: the start moment is in UTC, but the end moment isn't. Because I'm in BST (UTC+1), I'm ending up with a range that is always one hour short of the number of days I expect. Fixed version here.

[icambron]

Yeah, this has come up before (e.g. #15). Twix doesn't know that the start Moment is in UTC mode; it just creates a new Moment from the end argument; in fact it does little more than call moment() and use that. So yeah, the only thing to do here there:

moment.utc(start).twix(moment.utc(end));

//or

moment(start).utc().twix(moment(end).utc());

In theory I could fix this by checking isUTC() on the start Moment and then constructing the end moment differently, but that seems more confusing than anything else. What I would accept a PR for is an option in the option hash that let's you do:

moment.utc(start).twix(end, {utc: true});

and if so just calls .utc() after constructing the end.