Find missing entries within a sequence of data

with_sqlite_missing_dates.sql

WITH RECURSIVE
    days(day) AS (
        SELECT '2015-10-05T00:00:00Z'
        UNION ALL
        SELECT date(day,'+1 day') || 'T00:00:00Z' FROM days WHERE day < '2015-11-21T00:00:00Z'
    )
SELECT day, picks.title, picks.date FROM days LEFT JOIN picks ON picks.date = days.day WHERE picks.date IS NULL;