Started well, but pacing got very rushed [SPOILERS]

I started liking this effort --- largely because Donald Pleasance's character is so much fun --- but as the story moved on, it seemed to get more an more rushed, cutting from scene to scene without letting them sink in. Many characters --- especially the foursome involved in insect classification & adultery ---seemed like caricatures with dodgy accents.

Another issue I had with the pacing was judging the overall passage of time, when we had very few visual clues. How long was Miss Marple's stay? Did nine days really pass between Victoria's death and the denouement? What were they doing all that time?