You need to find 330 days before the day you want to go.

There are 365 days in a year. 365 minus 330 is 35 days. There are seven days in a week, so that is five weeks.

Take the day you want to go, look at a calendar, and go five weeks forward.

That is the date you can reserve tickets for, only a year earlier.

They may make you wait until it's 330 days from your return flight, but it's worth a shot.