diff --git a/covjsonkit/encoder/TimeSeries.py b/covjsonkit/encoder/TimeSeries.py
index 6508da0..b6c0413 100644
--- a/covjsonkit/encoder/TimeSeries.py
+++ b/covjsonkit/encoder/TimeSeries.py
@@ -194,11 +194,14 @@ def from_polytope(self, result):
                                 new_date = pd.Timestamp(date).strftime(date_format)
                                 start_time = datetime.strptime(new_date, date_format)
                                 # add current date to list by converting it to iso format
-                                try:
-                                    int(step)
-                                except ValueError:
-                                    step = step[0]
-                                stamp = start_time + timedelta(hours=int(step))
+                                if isinstance(step, timedelta):
+                                    stamp = start_time + step
+                                else:
+                                    try:
+                                        int(step)
+                                    except ValueError:
+                                        step = step[0]
+                                    stamp = start_time + timedelta(hours=int(step))
                                 coordinates[date][i]["t"].append(stamp.isoformat() + "Z")
                             break
                         break
diff --git a/covjsonkit/encoder/VerticalProfile.py b/covjsonkit/encoder/VerticalProfile.py
index b4c22b4..d7bd5ce 100644
--- a/covjsonkit/encoder/VerticalProfile.py
+++ b/covjsonkit/encoder/VerticalProfile.py
@@ -175,11 +175,14 @@ def from_polytope(self, result):
                     new_date = pd.Timestamp(date).strftime(date_format)
                     start_time = datetime.strptime(new_date, date_format)
                     # add current date to list by converting it to iso format
-                    try:
-                        int(step)
-                    except ValueError:
-                        step = step[0]
-                    stamp = start_time + timedelta(hours=int(step))
+                    if isinstance(step, timedelta):
+                        stamp = start_time + step
+                    else:
+                        try:
+                            int(step)
+                        except ValueError:
+                            step = step[0]
+                        stamp = start_time + timedelta(hours=int(step))
                     coordinates[date][i].append(
                         {
                             "latitude": [coords[date]["composite"][i][0]],
diff --git a/covjsonkit/version.py b/covjsonkit/version.py
index b5c9b6c..11ef092 100644
--- a/covjsonkit/version.py
+++ b/covjsonkit/version.py
@@ -1 +1 @@
-__version__ = "0.2.12"
+__version__ = "0.2.13"
diff --git a/pyproject.toml b/pyproject.toml
index 16b2f2b..e47fabc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,7 @@ markers = ["data: uses test data (deselect with '-m \"not data\"')",]
 
 [project]
 name = "covjsonkit"
-version = "0.2.12"
+version = "0.2.13"
 dependencies = [
     "pandas<3",
     "orjson",