Selecting only END DATE for time series produces wrong output

[demiangomez]

The time series is not plotted correctly when only the end date is provided

time series:

expected output is that the end date of the time series is 01/01/2020. This works correctly in pyETM, I think the problem is what is the filler for the start date.

[demiangomez]

Need to modify code here

Parallel.GAMIT/pgamit/pyETM.py

Line 2266 in 6717b18

if len(t_win) == 1:

to account for a tuple with [None, Date] so that the API can pass this when there is no begin date.