The Finnish Phoenix
How do you choose the time of the battle? My computer time is extremely limited and my time zone isn't USA. And when it'll be finished? From July 19 I'm not in home.
Match times are co-ordinated between paired players. So long as you're actively trying to connect with your opponent and provide your availability, I for my part would make every effort to facilitate communication across platforms, relay messages as to when each player will be available, and help ensure your match takes place as promptly as possible. That said, the tournament organizer has final say, and has put it in as terms as blunt as "If You don't show up , automatic forfeit." Given this, your situation of extremely limited computer time in an uncommon time zone with a hard deadline of July 19th is frankly less than ideal for you, your opponents, and the tournament as a whole. Efforts could be made as have been in past forum-hosted tournaments to pair you up with another player in a similar time zone, but eventually if you were to progress through the tournament you'd be paired up against someone in a different time zone. In the event you're paired up with an opponent that is making every effort to co-ordinate their match with you, has more time to commit to trying to meet you and you simply can't meet them because you don't have the time, there is a very real chance that the responsibility for that could be attributed to you and your situation of extremely limited computer time in which case you could be dropped if it's necessary for the tournament to progress. Given the history of OverSoul tournaments, there's also a very real chance for the tournament to drag out beyond July 19th despite every effort made to have matches take place in as timely a manner as they can. Given your unavailability beyond that point it would again be necessary to disqualify you for the tournament to progress in that case.
While I'd encourage you to join the tournament in spite of these challenges and would do my best to see that you're accommodated within reason, I'd be remiss not to mention them as considerations you'd have to make before entering.