@dcj @jsa-aerial Agreed; that does look like a bug. As an alternative to joining the Vega slack (which isn't a bad idea in its own right), you could just post an issue: https://github.com/vega/vega-lite/issues

@jsa-aerial @metasoarous maybe there is a way to do what I originally asked: https://stackoverflow.com/questions/54835983/vega-lite-how-to-specify-date-in-json-as-separate-fields-containing-year-month/54837454#54837454

@dcj Ah! Lovely! That's a wonderful solution. Thanks for updating us.

@dcj That's the ' add a transform to your spec which takes your year, month, day map and turns it into a legal temporal string and assigns that to a new field" that I mentioned. Very nice though that someone presented it so that we didn't need to figure it out! 😂

@jsa-aerial @metasoarous I just tried the code in the SO answer, it worked, BUT, month 2 was labelled as March! This is similar to the issue I had with days previously. My hypothesis is that some of the vega-lite fields are actually zero-based, not 1-based. So, for in this case, I changed the month calculation to be

datum.date.month - 1

@jsa-aerial @metasoarous When I RTFM, it is documented that month is zero based! https://vega.github.io/vega/docs/expressions/

Cool!