Combine two tables

[Andrej Pivk]

Hello.
I have two tables.
I would like to create querry which returns DateTime / Daily Working HH:MM:SS / AVERAGE Daily Temperature.
First table (Kotel) contains data of working hours. I make query to calculate daily hours (this works).
| ID | DateTime | Work_Skupaj_HH_HI | Work_Skupaj_HH_LO | Work_Skupaj_HH_MM | Work_Skupaj_HH_SS |

SELECT
(MAX(((Work_Skupaj_HH_HI * 10000) + Work_Skupaj_HH_LO)*3600 + (Work_Skupaj_MM * 60) + Work_Skupaj_SS) - MIN(((Work_Skupaj_HH_HI * 10000) + Work_Skupaj_HH_LO)*3600 + Work_Skupaj_MM * 60) + Work_Skupaj_SS) AS result_SSSS,
DateTime
FROM Kotel
WHERE DateTime >= '2021-10-11 00:00:00' AND DateTime <= '2021-10-18 23:59:59'
GROUP BY YEAR(DateTime), MONTH(DateTime), DAY(DateTime)


Second table (Senzorji) contains data of temperature. I got daily average by
| ID | DateTime | Senzor | Temperatura |
SELECT
AVG(Temperatura) AS result_Temp,
DateTime
FROM Senzorji
WHERE DateTime >= '2021-10-11 00:00:00' AND DateTime <= '2021-10-18 23:59:59' AND Senzor = 'Senzor3'
GROUP BY YEAR(DateTime), MONTH(DateTime), DAY(DateTime)


I tried JOIN command but I don't get expected results.
SELECT
s1.DateTime,
s2.DateTime,
(MAX(((s1.Work_Skupaj_HH_HI * 10000) + s1.Work_Skupaj_HH_LO)*3600 + (s1.Work_Skupaj_MM * 60) + s1.Work_Skupaj_SS) - MIN(((s1.Work_Skupaj_HH_HI * 10000) + s1.Work_Skupaj_HH_LO)*3600 + s1.Work_Skupaj_MM * 60) + s1.Work_Skupaj_SS) Cas,
s2.result_Temp Tpovpr
FROM Kotel s1
-- WHERE DateTime >= '2021-10-11 00:00:00' AND DateTime <= '2021-10-18 23:59:59'
-- GROUP BY YEAR(DateTime), MONTH(DateTime), DAY(DateTime)

left join
(
SELECT
AVG(Temperatura) AS result_Temp,
DateTime
FROM Senzorji
WHERE DateTime >= '2021-10-11 00:00:00' AND DateTime <= '2021-10-18 23:59:59' AND Senzor = 'Senzor3'
GROUP BY YEAR(DateTime), MONTH(DateTime), DAY(DateTime)
) s2
on s1.DateTime = s2.DateTime

Please help.
Thanks.