[aWATTar] fix counddown and remaining time (openhab#17067)

Signed-off-by: Thomas Leber <[email protected]>

Author: tl-photography

bundles/org.openhab.binding.awattar/src/main/java/org/openhab/binding/awattar/internal/handler/AwattarBestPriceHandler.java

@@ -44,7 +44,9 @@
 import org.openhab.binding.awattar.internal.AwattarPrice;
 import org.openhab.core.i18n.TimeZoneProvider;
 import org.openhab.core.library.types.OnOffType;
+import org.openhab.core.library.types.QuantityType;
 import org.openhab.core.library.types.StringType;
+import org.openhab.core.library.unit.Units;
 import org.openhab.core.thing.Bridge;
 import org.openhab.core.thing.Channel;
 import org.openhab.core.thing.ChannelUID;
@@ -195,12 +197,16 @@ public void refreshChannel(ChannelUID channelUID) {
                 diff = result.getStart() - Instant.now().toEpochMilli();
                 if (diff >= 0) {
                     state = getDuration(diff);
+                } else {
+                    state = QuantityType.valueOf(0, Units.MINUTE);
                 }
                 break;
             case CHANNEL_REMAINING:
-                diff = result.getEnd() - Instant.now().toEpochMilli();
                 if (result.isActive()) {
+                    diff = result.getEnd() - Instant.now().toEpochMilli();
                     state = getDuration(diff);
+                } else {
+                    state = QuantityType.valueOf(0, Units.MINUTE);
                 }
                 break;
             case CHANNEL_HOURS: