Missing submissions when pulling with --start_from_date in different timezones

[ggalmazor]

Problem description

Given a computer at UTC+1 with Briefcase and a server at UTC+0 with Aggregate, when Briefcase CLI pulls a form adding --start_from_date 2019-01-01, then submissions belonging to 23:00Z (from the day before) and 0:00Z are not pulled.

Steps to reproduce the problem

PENDING:

• Provide a form and submissions to recreate the scenario
• Provide Briefcase CLI command

Expected behavior

All submissions from the day coinciding with the value provided in the --start_from_date arg should be included.