Tasks is one single list with everything outstanding across all your grants at once, sorted by when it's due and not by which grant it belongs to. Two different things live in it, and it's worth knowing which is which.
Tasks have a tick box
These are the ones someone writes. Some you write yourselves; others appear on their own: when you register a grant, the documents its rules require are copied over, if that call for applications (convocatoria) has already been through the AI reading. Each task can carry a date, the person in your organisation who's on it and a note.
Deadlines don't
Applying before the call closes, the decision you're waiting on, the window to file representations (alegaciones) and the reporting date aren't stored anywhere: they're worked out from the dates each grant already has. That's deliberate. Storing them would create two truths – you correct the date on the record and the task still shows the old one – and once a deadline has lied to you, nobody looks at that list again.
That's why a deadline can't be ticked off either: it closes when you do the thing. The one for applying disappears when you move the grant to “Submitted”; the one for representations, when you enter the filing date on the Representations tab.
Everything is grouped by how close it is: overdue, today and tomorrow, this week, this month, later on, and no date. The cut-offs are counted in days and not in calendar weeks, so that “this week” means the same on a Monday as on a Friday.
Inside a grant's record you get the same list, but only its own, on its Tasks tab. There the done ones show crossed out and can be hidden: that list isn't a to-do list, it's the case file of what that call asks for, and what you've handed in matters as much as what's still missing.