Canada

Here's my theory: Carney dropped the DST because of supply management on dairy. My evidence is sparse, but:

Last month, the U.S. and Britain announced a trade deal related to a range of products. But Britain’s 2-per-cent DST was not affected.

(From the Globe)

That shows other countries have a DST but that hasn't been a sticking point in trade negotiations.

Meanwhile, Quebec really likes supply management:

83 per cent of Quebecers want governments to do everything in their power to protect the country’s supply management system.

During the next election, Carney will probably need Quebec's support to stay in power. By giving up the DST, Carney may be able to keep supply management for dairy, and avoid alienating Quebec voters.

I guess we'll see during the final negotiations. Do our dairy farmers get to keep their protections?