This?
WHERE file.cday != date(today)
EDIT
Note that this doesn’t work with TASK queries, because in TASK queries the filter WHERE (added in the last versions) seems to not work with in the same way with ‘pages’.
It these cases the WHERE filter priority seems to be ‘tasks’, not ‘pages’ (files/notes).
To works seems necessary to add another “file” before. Something like this:
```dataview
TASK
FROM "Daily"
WHERE !completed AND file.file.cday != date(today)
```