What problem does this feature solve?

x-Axis label in x-axis and tooltip
having the option to set different labels

What does the proposed API look like?

A) current:
xAxis: { data: ["J", "F", "M", "J" ... ] }

What would be expected?

B) Idea:
xAxis: { data: [{{"xAxis":"J", "tooltip": "January", "tooltip-explanation": "was a very cold month"}, {"xAxis": "F", "tooltip":"February", "tooltip-explanation": "was as cold as January"}}, ... ] }

A) should be possible futhermore