Writer-director Paul Morrison has fashioned an endearingly sweet later-in-life romance fable that follows two senior citizens who first meet walking their dogs and then, over the course of several seasons, deal with the joys, pittfalls and pains of what it means to start a relationship at any age, never mind in the autumn of the year.

Right away we meet Dave (Dave Johns, exquisite in “I, Daniel Blake”), when he and his dog