How far in advance to book train tickets?

Hi all, just wondering how far in advance I can/should book train tickets (Taitie, slow train, not high-speed). I’m planning heading to Hualien for Tomb Sweeping Festival in April and on the official website, it looks like you can only book up to 2 weeks in advance. If I buy in person at Taiwan Main Station can I buy further in advance? Or still have to wait until 2 weeks in advance? Any advice? I figure this will be a very busy travel time and don’t want to miss out…

I’ve only ever been able to book 2 weeks ahead of time (online), except for CNY which begins the booking process earlier. From what I read on the website, it appears that you can purchase Group and Season tickets more than 2 weeks prior to traveling.

I’m also curious if you can purchase tickets more than two weeks ahead of time directly at the station. I need a ticket for March and will try to do this today or tomorrow. I’ll report the results here for you.

Yesterday the clerk at Taipei main station confirmed that train tickets can be purchased only two weeks in advance.

Cool, thanks for letting me know.