diff --git a/timer.py b/timer.py
index 872a027..bad1798 100755
--- a/timer.py
+++ b/timer.py
@@ -24,18 +24,19 @@ DATETIME_FORMAT = [
 class DateTime(click.DateTime):
     def _try_to_convert_date(self, value: t.Any, format: str) -> t.Optional[datetime]:
         try:
-            if format == DELTASECONDS and value[-1] == "s":
-                return datetime.datetime.now() + datetime.timedelta(
-                    seconds=int(value[1:-1])
-                )
-            if format == DELTAMINUTES and value[-1] == "m":
-                return datetime.datetime.now() + datetime.timedelta(
-                    minutes=int(value[1:-1])
-                )
-            if format == DELTAHOURS and value[-1] == "h":
-                return datetime.datetime.now() + datetime.timedelta(
-                    hours=int(value[1:-1])
-                )
+            if value[0] == "+":
+                if format == DELTASECONDS and value[-1] == "s":
+                    return datetime.datetime.now() + datetime.timedelta(
+                        seconds=int(value[1:-1])
+                    )
+                if format == DELTAMINUTES and value[-1] == "m":
+                    return datetime.datetime.now() + datetime.timedelta(
+                        minutes=int(value[1:-1])
+                    )
+                if format == DELTAHOURS and value[-1] == "h":
+                    return datetime.datetime.now() + datetime.timedelta(
+                        hours=int(value[1:-1])
+                    )
             if format == HOURS:
                 return datetime.datetime.combine(
                     datetime.datetime.now().date(),