diff --git a/app/api/v1/endpoints/price.py b/app/api/v1/endpoints/price.py
index cde3185..65735e6 100644
--- a/app/api/v1/endpoints/price.py
+++ b/app/api/v1/endpoints/price.py
@@ -310,11 +310,19 @@ async def get_price_data_simple(
     period: Optional[str] = Query(None, description="Period like '1d', '7d', '1m', '3m', '6m', '1y', '2y', '5y', 'max'"),
     start_date: Optional[date] = Query(None, description="Start date for data retrieval (use with end_date, not with period)"),
     end_date: Optional[date] = Query(None, description="End date for data retrieval (use with start_date, not with period)"),
+    start: Optional[date] = Query(None, description="Alias for start_date"),
+    end: Optional[date] = Query(None, description="Alias for end_date"),
     interval: str = Query("1d", description="Data interval: 1d, 1w, 1m, 5d, 1h, etc."),
     force_refresh: bool = Query(False, description="Force refresh from Yahoo Finance"),
     db: AsyncSession = Depends(get_db)
 ):
     """Simplified GET endpoint for price data"""
+    # Resolve aliases: start/end → start_date/end_date
+    if start and not start_date:
+        start_date = start
+    if end and not end_date:
+        end_date = end
+
     # Validate that either period OR date range is provided, not both
     if period and (start_date or end_date):
         raise HTTPException(
diff --git a/app/schemas/financial.py b/app/schemas/financial.py
index 2428fdd..5e42772 100644
--- a/app/schemas/financial.py
+++ b/app/schemas/financial.py
@@ -145,8 +145,8 @@ class BulkFinancialDataRequest(BaseModel):
         if not quarters:  # Using date-based approach
             if not v:
                 raise ValueError("end_date is required when not using quarters")
-            if start_date and v <= start_date:
-                raise ValueError("end_date must be after start_date")
+            if start_date and v < start_date:
+                raise ValueError("end_date must be on or after start_date")
         return v
 
 class PriceDataRequest(BaseModel):
@@ -215,8 +215,8 @@ class PriceDataRequest(BaseModel):
         if not quarters:  # Using date-based approach
             if not v:
                 raise ValueError("end_date is required when not using quarters")
-            if start_date and v <= start_date:
-                raise ValueError("end_date must be after start_date")
+            if start_date and v < start_date:
+                raise ValueError("end_date must be on or after start_date")
         return v
 
 class BulkPriceDataRequest(BaseModel):
@@ -274,8 +274,8 @@ class BulkPriceDataRequest(BaseModel):
         if not quarters:  # Using date-based approach
             if not v:
                 raise ValueError("end_date is required when not using quarters")
-            if start_date and v <= start_date:
-                raise ValueError("end_date must be after start_date")
+            if start_date and v < start_date:
+                raise ValueError("end_date must be on or after start_date")
         return v
 
 
diff --git a/app/schemas/validators.py b/app/schemas/validators.py
index 7f54867..36e6300 100644
--- a/app/schemas/validators.py
+++ b/app/schemas/validators.py
@@ -57,6 +57,6 @@ def validate_end_date_field(cls, v, values):
     if not quarters and not period:  # Using date-based approach
         if not v:
             raise ValueError("end_date is required when using date range approach")
-        if start_date and v <= start_date:
-            raise ValueError("end_date must be after start_date")
+        if start_date and v < start_date:
+            raise ValueError("end_date must be on or after start_date")
     return v
\ No newline at end of file