If the channel on which you set the timer broadcasts series link info, then you can't alter the time, as it's assumed to be using the Accurate Recording feature.
If there is no series link info, then pressing Record will allow you to alter the details - you'll be asked if you want to record by time of day, rather than programme name first.
You can create a timer manually via the menu, and set it to whatever you want. You don't need to set the name when you do that - if you leave it blank, it will be set at recording time, based on the name of the programme from now&next.
If you don't use the built in series link, then I'd suggest you swap firmwares to 5.13.65NitFix, which doesn't have series link but is more stable and reliable overall, and will let you amend timers more fully.