diff --git a/src/credentials/CHIPCert.cpp b/src/credentials/CHIPCert.cpp
index 7f11430cd2a634..8dd1a9797d13ed 100644
--- a/src/credentials/CHIPCert.cpp
+++ b/src/credentials/CHIPCert.cpp
@@ -384,11 +384,15 @@ CHIP_ERROR ChipCertificateSet::ValidateCert(const ChipCertificateData * cert, Va
     {
         if (context.mEffectiveTime.Get<CurrentChipEpochTime>().count() < cert->mNotBeforeTime)
         {
+            ChipLogDetail(SecureChannel, "Certificate's mNotBeforeTime (%" PRIu32 ") is after current time (%" PRIu32 ")",
+                          cert->mNotBeforeTime, context.mEffectiveTime.Get<CurrentChipEpochTime>().count());
             validityResult = CertificateValidityResult::kNotYetValid;
         }
         else if (cert->mNotAfterTime != kNullCertTime &&
                  context.mEffectiveTime.Get<CurrentChipEpochTime>().count() > cert->mNotAfterTime)
         {
+            ChipLogDetail(SecureChannel, "Certificate's mNotAfterTime (%" PRIu32 ") is before current time (%" PRIu32 ")",
+                          cert->mNotAfterTime, context.mEffectiveTime.Get<CurrentChipEpochTime>().count());
             validityResult = CertificateValidityResult::kExpired;
         }
         else
@@ -407,6 +411,8 @@ CHIP_ERROR ChipCertificateSet::ValidateCert(const ChipCertificateData * cert, Va
         // certificate in question is expired.  Check for this.
         if (cert->mNotAfterTime != 0 && context.mEffectiveTime.Get<LastKnownGoodChipEpochTime>().count() > cert->mNotAfterTime)
         {
+            ChipLogDetail(SecureChannel, "Certificate's mNotAfterTime (%" PRIu32 ") is before last known good time (%" PRIu32 ")",
+                          cert->mNotAfterTime, context.mEffectiveTime.Get<LastKnownGoodChipEpochTime>().count());
             validityResult = CertificateValidityResult::kExpiredAtLastKnownGoodTime;
         }
         else
diff --git a/src/darwin/Framework/CHIP/MTROperationalCredentialsDelegate.mm b/src/darwin/Framework/CHIP/MTROperationalCredentialsDelegate.mm
index 8b703e4b317b9b..3688c9a08f7433 100644
--- a/src/darwin/Framework/CHIP/MTROperationalCredentialsDelegate.mm
+++ b/src/darwin/Framework/CHIP/MTROperationalCredentialsDelegate.mm
@@ -172,10 +172,8 @@
 bool MTROperationalCredentialsDelegate::ToChipEpochTime(uint32_t offset, uint32_t & epoch)
 {
     NSDate * date = [NSDate dateWithTimeIntervalSinceNow:offset];
-    unsigned units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute
-        | NSCalendarUnitSecond;
     NSCalendar * calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
-    NSDateComponents * components = [calendar components:units fromDate:date];
+    NSDateComponents * components = [calendar componentsInTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0] fromDate:date];
 
     uint16_t year = static_cast<uint16_t>([components year]);
     uint8_t month = static_cast<uint8_t>([components month]);