Issue with development date in triangle

[andrichviljoen]

Hi, I am relatively new to using this amazing package. I am getting some weird development and valuation dates in the triangles that I create! The development dates in the Triangle are 3 months later than the development dates in the original data, and I can't figure out why this is happening. I have updated pandas to 1.5.3 as I saw other users having issues with pandas > 2.0.

Create triangle:
actuals_tri = cl.Triangle(data = actuals_df, origin = 'Origin', development = 'Development', columns = 'Paid', index = 'Source', cumulative = True ,development_format = 'yyyy-mm-dd',origin_format = 'yyyy-mm-dd')

The data types in the actuals_df for both Origin and Development are datetime64[ns].

actuals_df:

actuals_tri.dev_to_val().to_frame()

As you can see, the developement dates in the actuals_tri Triangle are 3 months later than the development dates in the original data (i.e., actuals_df). Note that all the dates in the original data are either end of June or end of December.

Can you please provide guidance on why this may be happening?