It’s busy in town at the moment, being English half-term – I’d avoid anything cheeky before about 3pm. I’d also avoid that figure of eight ride around the back of Skiddaw – it’s a very dull ride. Glenderaterra in the morning and Borrowdale in the afternoon would be a better all-dayer.
Also worth considering Helvellyn from town – four hour round trip if you carry up Sticks and come down Birk Side (or up from Swirls and down Sticks is good too). Thirlmere over to Watendlath and down to Rosthwaite would add another hour or so – can be a bit wet coming over by Blea Tarn though.