The Financial Post reports in its Wednesday edition that Amazon's Prime Day is slamming into President Donald Trump's trade war, with ever-shifting tariffs prompting some brands to sit out the summer sale and some shoppers dropping hints they plan to pull back. A Bloomberg dispatch to the Post says the event, which began Tuesday and lasts four days, could provide prognosticators a glimpse of how much consumers are spending and what they are buying amid mixed signals about the strength of the U.S. economy. "Prime Day will provide an early indication on consumer appetite, especially in categories like apparel, electronics and TVs, where price drops are expected to be the deepest," said Vivek Pandya, analyst at Adobe, which expects Amazon and other U.S. retailers to generate $23.8-billion (U.S.) in on-line sales during the four-day event. Mr. Trump rattled global markets in April when he announced "Liberation Day" tariffs on 180 countries and territories, including China, but soon backed down after markets reacted. Mr. Trump restoked the unpredictability Monday with warnings to countries including Japan and South Korea that he would impose tariffs if trade deals were not reached by Aug. 1 -- but not necessarily Aug. 1.