diff --git a/icartt/dataset.py b/icartt/dataset.py
index 470a40bc5d132cda598733986dd8570b70a496b2..3fddd3fcae201a9e3952ce879f366629bf336529 100644
--- a/icartt/dataset.py
+++ b/icartt/dataset.py
@@ -231,7 +231,7 @@ class Dataset:
         # value is set to 0. The Mid-point time is required when it is not at the
         # average of Start and Stop times. For additional information see Section
         # 2.5 below.).
-        self.dataInterval = int(self.__readline()[0])
+        self.dataInterval = float(self.__readline()[0])
 
 
         # line 9 - Description or name of independent variable (This is the name
@@ -371,7 +371,7 @@ class Dataset:
         self.NVOL         = 1
         self.dateValid    = datetime.datetime.today()
         self.dateRevised  = datetime.datetime.today()
-        self.dataInterval = 0
+        self.dataInterval = 0.0
         self.IVAR         = Variable('Time_Start',
                                      'seconds_from_0_hours_on_valid_date',
                                      1.0, -9999999)