CRJ-700 Captain reported encountering wake turbulence departing ATL in trail of a B767-400.

Narrative

On today's flight from ATL-ZZZ we were assigned runway 27R for departure. As we get to the runway; we are number two behind a heavy 767-400. While the 767-400 was taking position; they were issued a takeoff clearance while still in the process of turning and lining up for the runway. Immediately after their response; we were issued a line-up and wait clearance and caution wake turbulence. When we saw it was about the time the 767 had takeoff thrust set; we began a timer using the aircraft clock for separation. Our clock was at the 1 minute mark and ATC issued our takeoff clearance. We requested an additional 30 seconds due to the timing. ATC cancelled our takeoff clearance and told us to advise when ready. Approximately 15 seconds later; another Controller came on the radio and asked us to state reason for delay in which we advised it was for wake turbulence separation. ATC responded in a scolding manner that they need to be advised when we need more than standard time for separation prior to taking the runway. We replied that we understand and we were ready for departure. We were then issued takeoff clearance by the original Controller and departed runway 27R. Approximately 1-2 minutes into the climb; we encountered wake turbulence. The aircraft rolled to the left abruptly twice within 30 seconds approximately 10 degrees each time. During the turbulence encounter; we were issued a new clearance direct to a new fix which aided in escaping the wake turbulence. The flight continued to destination as planned with no other issues.Cause: Event initially occurred due to improper spacing for wake turbulence between medium and heavy aircraft.Suggestions: It appeared that ATC was issuing takeoff clearance based on when the clearance was given instead of when the leading aircraft began their takeoff roll.