Handling of none leap year time types (BODCDMSYS-3689)

[jpolton]

Some model output may not contain leap year days. Xarray seems to handle this data differently. A lot of routines should still work but any time manipulation might see problems.

An option for handling this would be to write a time_stretch() routine which is able to stretch this data onto a full year's calendar.

[thogar-computer]

@jpolton to update the description
@katavouta to provide an example of code that does this

[katavouta]

I sent a very simplistic python example to @thogar-computer (that includes two methods for transforming from 360 calendar year to 365/366 calendar year).

[lukegorman]

so we want to interpolate the date time dimension instead of just date time -> index (1,2,3,4...)?

[lukegorman]

do you want an interpolation or an extrapolation???

@roje-bodc has tried an extrapolation but the data does not look good for some reason