UPDATE
I've made some progress with this, so thought I would report my findings here in case it helps anyone else.
To summarise, I want to publish a Production schedule, grouped by days for distribution to clients and suppliers. The schedule could span 2 days or 3 weeks and needs time slots in 5 minute increments.
It's a bit clunky, but at the moment I have a views table displaying results pulled from the database. Relationships pull in from a separate content type the related Project title etc (the site needs to have multiple schedules for different projects). I then have exposed filters so that the user can exclude / include various results. Lovely!
One issue I had was storing the time field. As i need to group results by date (so that all entries for a given day group together - then are ordered by time asc) I found I needed separate time and date fields. Storing date and time in one field, meant that results were group by date and time (so all 8am entries on a given day were together, then all 10am entries etc). Not the desired result. Drupal 7 doesn't have a time only field (that i can find) so I had to drop back to Drupal 6. Shame. Two separate date type fields didn't work as date field needs a year (so i could have year, hour & minute).
I then used editview module to make it easier to edit the view. No edit view release for D7 yet though.