Importing Data from BIKA LIMS without Addon

Hi everyone,
I am trying to import data from our old BIKA instance to Senaite without using any addon just by using two JSON apis in a python script. The biggest issue I noticed so far is senaite json api does not allow to set a past date for fields such as date received or date published. Is there anyone used my approach of using the two JSON apis to migrate data? If so please let me know the steps you followed.
Thank you in advance.