listtables.py

"""
list IPython Hub Task History tables, and timestamps
"""
import os
import sqlite3

dbfile = os.path.expanduser("~/.ipython/profile_default/tasks.db")
# connect to
conn = sqlite3.connect(dbfile)
tables = [ r[0] for r in conn.execute("SELECT name from sqlite_master where type = 'table'") ]
# print the timestamp for the last task in each table, and the table name
for table in tables:
    c = conn.execute("SELECT submitted from '%s' ORDER by submitted DESC" % table)
    last_timestamp = c.next()[0].split('.')[0]
    c = conn.execute("SELECT submitted from '%s' ORDER by submitted ASC" % table)
    first_timestamp = c.next()[0].split('.')[0]
    print "%38s: %s - %s" % (table, first_timestamp, last_timestamp)

# with this info, you can start the Hub with a particular past database name:
# c.SQLiteDB.table = "_u_u_i_d"

Great! Will give this a shot.