SQL queries, select records with specific datatime occurrences (3 per week, 3 days in a row )

[andr ptt]

I'm studying MySQL and I stumbled on some exercises where I got no idea how to approach the problem.

I have 2 Tables:
sys_users containing id username
sys_user_sessions containing id user_id login_tstamp logout_tstamp

I have been asked to query:

All users that login at least 3 times a week in the past month
The most common session durations in 30 min blocks for the past month
Users who logged at least 3 consecutive days in the past 2 months

Link to tables: http s://drive.google.com/file/d/1XNKSMVVfUzPyDXmEnBl-BWUi9O17doTu/view?usp=share_link (remove space between http and s if you wish to download the tables)

What I managed to do currently:

$todayDate = 1639033043;
$oneMonthAgoDate = $todayDate - 2419200;

SELECT * FROM `sys_users`
INNER JOIN sys_user_sessions ON sys_users.id=sys_user_sessions.user_id
WHERE sys_user_sessions.login_tstamp
BETWEEN '" . strval($oneMonthAgoDate) . "'
AND '" . strval($todayDate) . "'
HAVING COUNT(DISTINCT sys_user_sessions.login_tstamp ) >= 3


EXPECTED RESULTS: test_comunic user