diff --git a/contracts/constants.sol b/contracts/constants.sol
index 9e6d9a5..5730cf8 100644
--- a/contracts/constants.sol
+++ b/contracts/constants.sol
@@ -6,3 +6,6 @@ uint256 constant EXP_SCALE = 1e18;
 
 /// @dev A unit (literal one) in EXP_SCALE, usually used in additions/subtractions
 uint256 constant MANTISSA_ONE = EXP_SCALE;
+
+/// @dev The approximate number of seconds per year
+uint256 constant SECONDS_PER_YEAR = 31_536_000;