No such thing as a daft question Dave!
However the answer to yours is full of ifs and buts.
Propagation varies day to day as the SFI and A & K indices change, there are also seasonal variations and of course the sunspot cycle to take into account. For "Good propagation" you want a high SFI and low A&K.
And as you'll no doubt know time of day influences the maximum usable frequency.
If you download W6ELProp (just do a web search for it) it allows you to enter current SFI and K values and then will calculate signal levels for any chosen band between your QTH and any other and will show on screen or print out tables and/or graphs.
I've been using it for around 20 years and have found it to be a good guide when planning skeds and contest strategy.
Back in the early 1990s I was QSL manager for an Antarctic station and we used W6ELProp to plan our weekly skeds and it was pretty reliable.
Dave
