There are two options for when recipes get built:
A build will be scheduled automatically once a change in any of the branches used in the recipe is detected.
If there has been a build of the recipe within the previous 24 hours into the daily build PPA, the build will not be scheduled until 24 hours since the last build into the daily build PPA.
If the recipe had been built within the last 24 hours into a different PPA using the "Request build" action, this will not delay the daily build.
If you really want the build to happen before the 24 hour period is up, you can use the "Request build" action.
Builds of the recipe have to be manually requested using the "Request build" action.