"Variable not found" error when loading original Trace21ka data files

[dinilu]

Hello!
I am trying to use loadeR to import original files from the Trace21ka experiment. I can import files from the most recent time periods (e.g. trace.36.400BP-1990CE.cam2.h0.TSMN.2160101-2204012.nc), but any other file for the same variable but different time period (e.g. trace.01.22000-20001BP.cam2.h0.TSMN.0000101-0200012.nc) fails with the following message:

di <- dataInventory("../Data/Trace21ka/TSMN/trace.01.22000-20001BP.cam2.h0.TSMN.0000101-0200012.nc")
[2020-08-07 17:54:12] Doing inventory ...
Error: No variables found
tsmx <- loadGridData(dataset = "../Data/Trace21ka/TSMX/trace.01.22000-20001BP.cam2.h0.TSMX.0000101-0200012.nc", var = "TSMX", lonLim = lon, latLim = lat, dictionary = FALSE)
Error: Variable requested not found
Check 'dataInventory' output and/or dictionary 'identifier'.

I have manually checked and compared both files and they look quite the similar but the units of the time dimension. The most recent periods (and working file) is "days since 0001-01-01 00:00:00" while the other files is "ka BP". Is there anything I am missing in order to load those files? Is this a known issue?

All the best and thank you for the helpfull packages of climate4R framework.
Diego

[dinilu]

Looking into this issue, it seems to me that loadeR is using a date format that doesn't allow to specify dates before year 0. I think this might be causing the issue since invalid date formats seems to results in a vector of NAs.