diff --git a/EngieApi/Contracts.py b/EngieApi/Contracts.py
index e10167c..f2f8843 100644
--- a/EngieApi/Contracts.py
+++ b/EngieApi/Contracts.py
@@ -8,7 +8,7 @@ from EngieApi.EngieAPI import EngieAPI
 
 
 class Dynamic:
-    def __init__(self, btw=1.21):
+    def __init__(self, btw=1.21, cache: bool = False):
         self.btw = btw
         self.vast = 100.7  # EUR / jaar
 
@@ -22,6 +22,7 @@ class Dynamic:
         # 20000 < kwh < 50000: 1.22748 cent / kWh
         # 50000 < kwh < 100000: 1.15540 cent / kWh
         self.federale_accijns = 0.0144160  # EUR / kWh
+        self.cache = cache
 
     def calculate_price_per_kwh(self, date, peak: float):
         """calculate_price_per_kwh
@@ -29,7 +30,7 @@ class Dynamic:
         :param date: date to calculate for
         :type date: date
         """
-        api = EngieAPI()
+        api = EngieAPI(cache=self.cache)
         epex_spot = np.array(api.get_epex_spot(date))
 
         prijs = 0.2040 + 0.1 * (epex_spot)  # zonder BTW per Cent/kWh
diff --git a/EngieApi/EngieAPI.py b/EngieApi/EngieAPI.py
index 2deff5a..98c9bba 100755
--- a/EngieApi/EngieAPI.py
+++ b/EngieApi/EngieAPI.py
@@ -8,7 +8,7 @@ date_format = "%Y-%m-%dT%H:%M:%S%z"
 
 
 class EngieAPI:
-    def __init__(self):
+    def __init__(self, cache: bool = False):
         self.url = "https://benergy-back.azurewebsites.net/api/gateway/mercure"
         self.headers = {
             "Host": "benergy-back.azurewebsites.net",
@@ -22,7 +22,21 @@ class EngieAPI:
             "Accept-Language": "en-GB,en;q=0.9",
         }
 
+        self.cache = cache
+        self.cache_file = "EngieCache.json"
+
     def get_epex_spot(self, date: date) -> List[float]:
+        if self.cache:
+            try:
+                with open("EngieCache.json", "r") as f:
+                    cache = json.load(f)
+                    print(cache)
+            except FileNotFoundError:
+                cache = {}
+
+            if date.strftime("%Y-%m-%d") in cache:
+                return cache[date.strftime("%Y-%m-%d")]
+
         to_date = datetime(date.year, date.month, date.day, 23, 59, 59)
         from_date = to_date - timedelta(days=1, hours=23, minutes=59, seconds=59)
 
@@ -40,10 +54,27 @@ class EngieAPI:
 
         values = []
         for j in res.json()[0]["Points"]:
+            print(j)
             # check if the Date is the same as the one requested, attention to the timezone
-            if datetime.strptime(j["Date"], date_format).date() == date:
+            if datetime.strptime(j["Date"], date_format).date().strftime(
+                "%Y-%m-%d"
+            ) == date.strftime("%Y-%m-%d"):
                 values.append(j["Value"])
 
+        if self.cache:
+            # check if the cache exists else create it
+            try:
+                with open("EngieCache.json", "r") as f:
+                    cache = json.load(f)
+            except FileNotFoundError:
+                cache = {}
+
+            # update cache
+            cache[date.strftime("%Y-%m-%d")] = values
+
+            with open("EngieCache.json", "w+") as f:
+                json.dump(cache, f)
+
         if not values:
             raise ValueError("No data found for this date")
         return values