question about otb

[ontheoutside]

i noticed that sometimes when a big race is on a saturday, you can bet that race on a friday through your otb acct on the computer

why dont they have something like that for people to bet there choices for the followoing day ?they can do it for the derby for example,why not everyy race for early betting?i know ill be cooped up on a paving machine all day today and will not be able to bet at all
with early betting i could get home and watch on replays
thanks