Yes standard for long haul is 40 minutes PA, 20 minutes to landing call.

For short haul it is 20 minute PA, 10 minutes to landing call. Sometimes you do get a 15 minute to landing call for short haul. After the 20 minute call from the flight deck there will usually be a PA straight after by one of the cc along the lines of "as we are about to land the seat belt signs will go on in approximately 10 minutes..." etc. There may also be a Flying Start PA as well between the 20 and 10 minute PAs - although when that is done all I can think of is Wish Wings!

In fact those will long memories may recall the LHR arrivals video being played prior to the 10 minute call