Show an indicator flag if testimony was submitted in the pre-hearing period

Comments are not official testimony associated with a hearing unless they are submitted (typically) between the time a hearing is announced and the time of the hearing. It would be nice to show an indicator flag if the comment was submitted in that window.

However, committees' rules vary, so there are no hard and fast rules, which will make this slightly challenging. We could use a general rule of thumb such as 'from -30 to +2 days from the hearing.'

https://cfb-public.slack.com/archives/C01H71R33FU/p1658339859896609?thread_ts=1658275707.657639&cid=C01H71R33FU