diff --git a/contracts/WeiTable.sol b/contracts/WeiTable.sol
index 437f679..0007a47 100644
--- a/contracts/WeiTable.sol
+++ b/contracts/WeiTable.sol
@@ -187,7 +187,7 @@ contract WeiTable is IWeiReceiver, Ownable {
 				return (e.balanceOnMomentReceived/e.totalWeiNeeded) + 1;
 			}		
 		} else if((e.isPeriodic) && (e.isSlidingAmount)) {
-			return 1 + ((block.timestamp - e.momentReceived) / (e.periodHours * 3600 * 1000));
+			return 1 + ((block.timestamp - e.momentCreated) / (e.periodHours * 3600 * 1000));
 		} else {
 			return 1;
 		}			
diff --git a/contracts/ether/WeiExpense.sol b/contracts/ether/WeiExpense.sol
index 37cfbf3..219c603 100644
--- a/contracts/ether/WeiExpense.sol
+++ b/contracts/ether/WeiExpense.sol
@@ -153,7 +153,7 @@ contract WeiExpense is IWeiReceiver, IDestination, Ownable {
 				return (balanceAtMomentReceived / totalWeiNeed) + 1;
 			}		
 		} else if((isPeriodic) && (isSlidingAmount)) {
-			return 1 + ((block.timestamp - momentReceived) / (periodHours * 3600 * 1000));
+			return 1 + ((block.timestamp - momentCreated) / (periodHours * 3600 * 1000));
 		}else {
 			return 1;
 		}