Tobago Express ticket - how far in advance??

[Rachana]

Hello all,

I am new to this website and forum, but it looks great so I thought I'd ask a question here! I would like to travel from Trinidad to Tobago on the evening of Sun, March 6 and return to Trinidad during the afternoon of Wed, March 9. My question is how far in advance do I need to buy this plane ticket for Tobago Express? Would it be possible to just buy a ticket on Sunday morning, if I'm not too picky about which evening flight I will take? Thanks for your input.

Rachana