NetCDF time units for seconds

ThomasPingel1 — Thu, 19 Oct 2023 16:57:09 GMT

Hi - I'm using ArcGIS to inspect a NetCDF we've created that represents a multidimensional raster created from fused lidar data. Each time slice is one second.

When we load it into ArcGIS Pro, the time isn't picked up correctly. In this sample dataset there are 60 time slices, each a second starting at 2023-04-10 12:35:00. When it gets loaded into ArcGIS Pro (Add Data -> Multidimensional Raster Layer), the time defaults to 2023-04-01 at 12:35am (00:35:00).

I've tracked this down to how the time.units string is formatted. When the string is formatted by xarray as we write it, it looks like this:

Variable attribute value: seconds since 2023-04-10T12:00:00

When I force it to remove the "T" (see attached revised file), ArcGIS Pro picks it up normally / as expected:

Variable attribute value: seconds since 2023-04-10 12:00:00

As far as I can tell, though, the use of the "T" is standard with ISO 8601. I can force the unit change and fix the problem on my NetCDFs, but I wonder if this isn't undesirable behavior on the ArcGIS side that should be patched.

topic NetCDF time units for seconds in ArcGIS Pro Questions

NetCDF time units for seconds