diff --git a/source/logic/helpers.ts b/source/logic/helpers.ts
index bf02a46..7914fc6 100644
--- a/source/logic/helpers.ts
+++ b/source/logic/helpers.ts
@@ -75,6 +75,42 @@ namespace _zeitbild.frontend_web.helpers
 	}
 	
 	
+	/**
+	 * @todo timezone
+	 */
+	export function date_format(
+		date : lib_plankton.pit.type_date
+	) : string
+	{
+		return lib_plankton.string.coin(
+			"{{year}}-{{month}}-{{day}}",
+			{
+				"year": date.year.toFixed(0).padStart(4, "0"),
+				"month": date.month.toFixed(0).padStart(2, "0"),
+				"day": date.day.toFixed(0).padStart(2, "0"),
+			}
+		);
+	}
+	
+	
+	/**
+	 * @todo timezone
+	 */
+	export function time_format(
+		time : lib_plankton.pit.type_time
+	) : string
+	{
+		return lib_plankton.string.coin(
+			"{{hour}}:{{minute}}",
+			{
+				"hour": time.hour.toFixed(0).padStart(2, "0"),
+				"minute": time.minute.toFixed(0).padStart(2, "0"),
+				"second": time.second.toFixed(0).padStart(2, "0"),
+			}
+		);
+	}
+	
+	
 	/**
 	 * @todo timezone
 	 */
@@ -89,14 +125,7 @@ namespace _zeitbild.frontend_web.helpers
 			return lib_plankton.string.coin(
 				"{{date}}{{macro_time}}",
 				{
-					"date": lib_plankton.string.coin(
-						"{{year}}-{{month}}-{{day}}",
-						{
-							"year": datetime.date.year.toFixed(0).padStart(4, "0"),
-							"month": datetime.date.month.toFixed(0).padStart(2, "0"),
-							"day": datetime.date.day.toFixed(0).padStart(2, "0"),
-						}
-					),
+					"date": date_format(datetime.date),
 					"macro_time": (
 						(datetime.time === null)
 						?
@@ -105,14 +134,7 @@ namespace _zeitbild.frontend_web.helpers
 						lib_plankton.string.coin(
 							",{{time}}",
 							{
-								"time": lib_plankton.string.coin(
-									"{{hour}}:{{minute}}",
-									{
-										"hour": datetime.time.hour.toFixed(0).padStart(2, "0"),
-										"minute": datetime.time.minute.toFixed(0).padStart(2, "0"),
-										"second": datetime.time.second.toFixed(0).padStart(2, "0"),
-									}
-								),
+								"time": time_format(datetime.time),
 							}
 						)
 					),
@@ -129,24 +151,28 @@ namespace _zeitbild.frontend_web.helpers
 		to : (null | lib_plankton.pit.type_datetime)
 	) : string
 	{
-		return lib_plankton.string.coin(
-			"{{from}}{{macro_to}}",
-			{
-				"from": datetime_format(from),
-				"macro_to": (
-					(to === null)
-					?
-					""
-					:
-					lib_plankton.string.coin(
-						" - {{to}}",
-						{
-							"to": datetime_format(to),
-						}
-					)
-				),
+		let result : string = "";
+		result += datetime_format(from);
+		if (to === null) {
+			// do nothing
+		}
+		else {
+			result += " - ";
+			if (
+				(from.date.year === to.date.year)
+				&&
+				(from.date.month === to.date.month)
+				&&
+				(from.date.day === to.date.day)
+			) {
+				// only time
+				result += time_format(to.time);
 			}
-		);
+			else {
+				result += datetime_format(to);
+			}
+		}
+		return result;
 	}
 	
 	/**