se scendete fino a ANNEX, trovate :
Annex
Effective with respect to goods (i) entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern daylight time on May 10, 2019, and (ii) exported to the United States on or after May 10, 2019, subchapter III of chapter 99 of the Harmonized Tariff Schedule of the United States is modified: 1. By amending U.S. Note 20(e) to subchapter III of chapter 99 by deleting “10 percent” each place that it appears, and inserting “25 percent” in lieu thereof; 2. by amending U.S. Note 20(g) to subchapter III of chapter 99 by deleting “10 percent” each place that it appears, and inserting “25 percent” in lieu thereof;

si tratta ora di capire cosa significa 12,01 am daylight time..
LINK https://www.npl.co.uk/resources/q-a/is-midnight-12am-or-12pm
By convention, 12 am refers to midnight at the start of the specified day (00:00 on the 24 hour clock) and 12 pm to midnight at the end of that day (24:00 on the 24 hour clock)

quindi le 12,01 am sarebbero la mezzanotte e un minuto alla partenza della data specificata (ossia l ora 00:00 di venerdi), ossia quella del 10 maggio, venerdi
Tradotto in orario nostro, i dazi dovrebbero scattare alle 6,oo di mattina di domani.