Fix floating point rounding error in FormatTime

ConsoleApp/src/Utils.cs

@@ -92,17 +92,15 @@ public static string FormatTime(double seconds) {
 			if (Math.Abs(seconds) > 8640000) // 10 days, probably happens from initializing the tick interval to garbage
 				return "invalid";
 			string sign = seconds < 0 ? "-" : "";
-			// timespan truncates values, (makes sense since 0.5 minutes is still 0 total minutes) so I round manually
-			TimeSpan t = TimeSpan.FromSeconds(Math.Abs(seconds));
-			int roundedMilli = t.Milliseconds + (int)Math.Round(t.TotalMilliseconds - (long)t.TotalMilliseconds);
+			TimeSpan t = TimeSpan.FromSeconds(Math.Round(Math.Abs(seconds), 3));
 			if (t.Days > 0)
-				return $"{sign}{t.Days:D1}.{t.Hours:D2}:{t.Minutes:D2}:{t.Seconds:D2}.{roundedMilli:D3}";
+				return $"{sign}{t.Days:D1}.{t.Hours:D2}:{t.Minutes:D2}:{t.Seconds:D2}.{t.Milliseconds:D3}";
 			else if (t.Hours > 0)
-				return $"{sign}{t.Hours:D1}:{t.Minutes:D2}:{t.Seconds:D2}.{roundedMilli:D3}";
+				return $"{sign}{t.Hours:D1}:{t.Minutes:D2}:{t.Seconds:D2}.{t.Milliseconds:D3}";
 			else if (t.Minutes > 0)
-				return $"{sign}{t.Minutes:D1}:{t.Seconds:D2}.{roundedMilli:D3}";
+				return $"{sign}{t.Minutes:D1}:{t.Seconds:D2}.{t.Milliseconds:D3}";
 			else
-				return $"{sign}{t.Seconds:D1}.{roundedMilli:D3}";
+				return $"{sign}{t.Seconds:D1}.{t.Milliseconds:D3}";
 		}