Check Your Software
After the time change, take a look at your ham radio software to make sure the clocks changed, or not changed, depending on the case, in your software. With the electronic QSL services, such as Logbook to the World, eQSL, QRZ.com, and others, if your log doesn't match his log within a few minutes, you don't get credit for the contact.
Reference to UTC/GMT
Daylight Saving Time: -7 Hours
Standard Time: -8 Hours