journay     date_start  date_end
1           1515200400  1515369600
2           1515805200  1515974400
3           1516410000  1516579200
4           1517014800  1517184000
5           1517619600  1517788800

select journay, DATE_ADD(FROM_UNIXTIME(max(date_game_large)), INTERVAL (9 - IF(DAYOFWEEK(FROM_UNIXTIME(max(date_game_large)))=1, 8, DAYOFWEEK(FROM_UNIXTIME(max(date_game_large))))) DAY) as NEXTMONDAY from tablaone GROUP by journay order by journay


id_competition  journay .   date_start  date_end
385 1   1515200400  2018-01-08 18:00:00
385 2   1515805200  2018-01-15 18:00:00
385 3   1516410000  2018-01-22 18:00:00
385 4   1517014800  2018-01-29 18:00:00
385 5   1517619600  2018-02-05 18:00:00