My guide team start at about 7am doing late changes for that day and the next full 7th day and the changes within them all, across all capital and regional channels. Sometimes we hold off on late changes if we are unsure. They finish at about 5 -6pm. As long as you have a PVR that logs in every 15 minutes and it can cope with timer changes, as the Beyonwiz V/U/T series can (but some earlier ones had problems and would use a second timer for the update hence holding off as a second change wouldn't find a tuner plus other issues), then final changes will be updated in its guide. So just set it now and it will auto-correct via IceTV to whatever time it finally airs. Getting impatient is pointless as the staff have to go home and, with a new PVR, just set it and it will change via the PVR login and IceTV for updates according to any change that may occur. Please be sure we are aware of discrepancy you now see, or are thankful that a forum post has alerted us, but the staff can't work 12 hours a day and we will update tomorrow.
With sport that runs over, and cricket is the prime example, we haven't got a crystal ball so have to go with the length of the show that the channel dictates however the simple solution is to always record the following show as well, or even two shows depending on their length. Then you can be sure to capture it all.