Axis with d3.scaleTime scale and specified number of ticks is apparently mislabelled

[robinhouston]

An axis that uses a date scale (d3.scaleTime) and has a specified number of ticks (.ticks(6)) is apparently mislabelled. All the ticks are labelled with the string "6".

See demo here.

[robinhouston]

Sorry, my mistake. This is documented behaviour:

These arguments are also passed to the scale’s tickFormat method to generate a tick format (unless a tick format is specified explicitly via axis.tickFormat)

Is there any way to specify the number of ticks while retaining the default tick format?

[robinhouston]

So, one can do it like this:

axis.ticks(5).tickFormat(scale.tickFormat());

That feels a little bit convoluted, though.

[mbostock]

Yeah, I think this is a bug. The problem is that the time scale’s tickFormat method isn’t consistent with the other scales, which all take a suggested count as the first argument.

In D3 3.x this wasn’t an issue because the time scale ignored all arguments to scale.tickFormat. So, if you specified a count to axis.ticks, it would affect scale.ticks, but not scale.tickFormat (because a time scale always renders times the same way, dependent only on the input time and not the number of ticks).

We should retain that behavior for D3 4.0.