Fix date range negative month

htdocs/DateRangePicker.vue

@@ -53,8 +53,8 @@
 	}
 
 	function timeshift_month(date, diff) {
-		var month = date.getMonth() + diff;
-		return new Date(date.getFullYear() + Math.floor(month/12), month >= 0 ? (month%12) : (month%12 + 12), date.getDate());
+		var month = date.getMonth() + diff, month_mod12 = month%12;
+		return new Date(date.getFullYear() + Math.floor(month/12), month_mod12 >= 0 ? (month_mod12) : (month_mod12 + 12), date.getDate());
 	}
 
 	function datecalc(date, range, direction) {

htdocs/ViewData.vue

@@ -226,7 +226,7 @@
 		},
 		watch: {
 			async resultset(value) {
-				this.$nextTick(() => this.$refs.headers ? this.$refs.headers.scrollIntoView({ block: 'nearest', inline: 'end' }) : null);
+				this.$nextTick(() => (this.$refs.headers) && (this.$refs.headers.length > 0) ? this.$refs.headers[this.$refs.headers.length - 1].scrollIntoView({ block: 'nearest', inline: 'end' }) : null);
 			}
 		},
 		methods: {