Solution : https://service.sap.com/sap/support/notes/680394 (SAP Service marketplace login required)
Key words : 
daylight saving timethe errors, front-end network time, client server technology area, icm/http/server_cache_00/expiration, daylight saving time release 6, big time diff, terms disp+work, rfc-sdk solution, work process runs, icm patch collection
Related Notes : 
       
| 679918 | The front-end network time | 
| 679615 | |
| 672272 | 64-enabled statistics | 
| 670165 | RFC and HTTP check in the Dispatcher | 
| 642340 | |
| 508300 | ICM Patch Collection (Release 6.20) |