diff --git a/plot_wf_longterm.py b/plot_wf_longterm.py
index 0b5f22d..b07ca9d 100755
--- a/plot_wf_longterm.py
+++ b/plot_wf_longterm.py
@@ -161,21 +161,23 @@ print("Formatting...")
 
 ax.yaxis_date()
 
-#ax.yaxis.set_major_locator(HourLocator(range(0, 25, 1)))
-#ax.yaxis.set_minor_locator(MinuteLocator(range(0, 60, 20)))
-#ax.yaxis.set_major_formatter(DateFormatter('%H:%M'))
-#ax.yaxis.set_minor_formatter(DateFormatter('%M'))
+if len(args.input) == 1:
+    # only one argument means that we plot at most 1 day. Use Hour and Minute
+    # locators for nicer formatting.
+    ax.yaxis.set_major_locator(HourLocator(range(0, 25, 1)))
+    ax.yaxis.set_minor_locator(MinuteLocator(range(0, 60, 20)))
+    ax.yaxis.set_major_formatter(DateFormatter('%H:%M'))
+    ax.yaxis.set_minor_formatter(DateFormatter('%M'))
+else:
+    # we are plotting multiple files and therefore probably a long time. Use
+    # Day and Hour locators.
 
-#loc = AutoDateLocator()
-#ax.yaxis.set_major_locator(loc)
-#ax.yaxis.set_major_formatter(DateFormatter('%Y-%m-%d %H:%M'))
+    ax.yaxis.set_major_locator(DayLocator(interval=max(1, args.resolution // 600)))
+    ax.yaxis.set_major_formatter(DateFormatter('%Y-%m-%d'))
 
-ax.yaxis.set_major_locator(DayLocator(interval=max(1, args.resolution // 600)))
-ax.yaxis.set_major_formatter(DateFormatter('%Y-%m-%d'))
-
-if args.resolution <= 600:
-    ax.yaxis.set_minor_locator(HourLocator(interval=max(1, args.resolution // 100)))
-    ax.yaxis.set_minor_formatter(DateFormatter('%H'))
+    if args.resolution <= 600:
+        ax.yaxis.set_minor_locator(HourLocator(interval=max(1, args.resolution // 100)))
+        ax.yaxis.set_minor_formatter(DateFormatter('%H'))
 
 ax.xaxis.set_major_locator(MultipleLocator(1.0))
 ax.set_xlabel('Frequenz [MHz]')