diff --git a/src/marketdata/input_types/stocks.py b/src/marketdata/input_types/stocks.py
index cf10534..f814cd2 100644
--- a/src/marketdata/input_types/stocks.py
+++ b/src/marketdata/input_types/stocks.py
@@ -4,6 +4,7 @@
 from pydantic import Field, field_validator, model_validator
 
 from marketdata.input_types.base import BaseInputType, BaseModelConfig
+from marketdata.utils import format_timestamp
 
 
 class StocksPricesInput(BaseInputType):
@@ -48,11 +49,11 @@ class StocksCandlesInput(BaseInputType):
 
     resolution: str = Field(description="The resolution to use", default="D")
 
-    from_date: datetime.date | str | None = Field(
+    from_date: datetime.date | datetime.datetime | str | None = Field(
         description="The start date to fetch candles for", default=None, alias="from"
     )
 
-    to_date: datetime.date | str | None = Field(
+    to_date: datetime.date | datetime.datetime | str | None = Field(
         description="The end date to fetch candles for", default=None, alias="to"
     )
 
@@ -71,6 +72,24 @@ class StocksCandlesInput(BaseInputType):
     @model_validator(mode="after")
     def validate_input(self) -> "StocksCandlesInput":
         self._validate_min_max_dates("from_date", "to_date")
+
+        if self.is_intraday:
+            # Intraday resolution needs datetime objects to work with split_dates_by_timeframe
+            # But str is allowed in the input type for "yesterday" and others.
+            # So Pydantic will skip the validation for str, and we need to convert str to datetime objects here.
+            if isinstance(self.from_date, str):
+                self.from_date = format_timestamp(self.from_date)
+            if isinstance(self.to_date, str):
+                self.to_date = format_timestamp(self.to_date)
+
+            if isinstance(self.from_date, datetime.date):
+                self.from_date = datetime.datetime.combine(
+                    self.from_date, datetime.time.min
+                )
+            if isinstance(self.to_date, datetime.date):
+                self.to_date = datetime.datetime.combine(
+                    self.to_date, datetime.time.min
+                )
         return self
 
     @field_validator("resolution")
diff --git a/src/marketdata/resources/stocks/candles.py b/src/marketdata/resources/stocks/candles.py
index a3cc450..107e35b 100644
--- a/src/marketdata/resources/stocks/candles.py
+++ b/src/marketdata/resources/stocks/candles.py
@@ -80,7 +80,7 @@ def _get_response(
         if input_params.is_intraday:
             year_ranges = split_dates_by_timeframe(
                 input_params.from_date,
-                input_params.to_date or datetime.date.today(),
+                input_params.to_date or datetime.datetime.now(),
                 datetime.timedelta(days=365),
             )
         else:
diff --git a/src/tests/test_stocks_candles.py b/src/tests/test_stocks_candles.py
index bc53258..fe686d1 100644
--- a/src/tests/test_stocks_candles.py
+++ b/src/tests/test_stocks_candles.py
@@ -444,3 +444,21 @@ def test_get_stocks_candles_response_200_csv(respx_mock, client):
         filename="test.csv",
     )
     assert pathlib.Path(output).read_text() is not ""
+
+
+def test_stocks_candles_intraday_string_dates(load_json, respx_mock, client):
+    mock_data = load_json("stocks_candles_response_200")
+
+    respx_mock.get("https://api.marketdata.app/v1/stocks/candles/4H/AAPL/").respond(
+        json=mock_data,
+        status_code=200,
+    )
+
+    candles = client.stocks.candles(
+        symbol="AAPL",
+        resolution="4H",
+        from_date="2023-01-01",
+        to_date="2023-01-05",
+        output_format=OutputFormat.INTERNAL,
+    )
+    assert len(candles) == 253