> Think of the last time you had a bad night sleep. You feel bad the next day, but the next night if you sleep well, you'll feel fully recovered from that bad night. But when we spring forward, we often feel bad for weeks. Why does losing that hour have such a profound effect? It is because we are shifted into a state of permanent jet lag with the time change. Your circadian clock follows dawn. The dawn on March 13th in Calgary is at 6:53am, but on DST the next day it is at 7:51am.
(I emphasized the relevant sentence)
I certainly don't feel bad for weeks after the start of DST, I literally don't know what he's talking about. And, if anything, if I feel sleep deprived it's usually because I go to sleep later because I much enjoy having an extra hour of daylight in the evening.