Selecting distinct rows from two tables, using multiple conditions
Schematically:

SELECT offices.id
-- join tables
FROM offices
JOIN meetings ON offices.id = meetings.office_id
-- select only rows for Jan and Feb 2020
WHERE DATE(meeting_date) BETWEEN '2020-01-01' AND '2020-02-29'
-- grouping - prepare calculations for separate offices
GROUP BY offices.id
-- check that the amount of `allowed_lunch` in Feb is zero
HAVING NOT SUM(DATE(meeting_date) BETWEEN '2020-02-01' AND '2020-02-29' AND allowed_lunch)
-- but total is not zero (taking into account prev. check - they're in Jan)
   AND SUM(allowed_lunch)