6or7silver craft seen at extreme height moving to different fomations

werewe 
This was not the sighting of UFOs as I had imagined it to be.
The time was 1900 1930hrs,bright sun in the west.My neighbour was working under next door neighbour's van,when he slid out on his board he was in the shade,he wouldn't have seen them otherwise.
We were all(van owner,his mother and me)called to see,or try to.
The sky was clear,aircraft from UK airports plainly visible at a variety of heights,we in Derby are under the flight path of all North bound  traffic.
The objects,6 or 7 of them were barely visible as they were at such extreme height,standing in the sun they proved difficult to spot,but once found they were easy to keep in focus,but not so easy with binoculars at the distance.
They seemed to have an agenda as they moved separately to make new formations.
All the time, aircraft were passing below them,some were so high and could only be seen as aircraft with binoculars,which gives some idea as to the altitude of the objects.(I would guess between 100000 and 200000ft).The sun made them shine silver,how big they were I dread to think if we could see themso far up.
Witness does not specify a date for the alleged sighting.  PD