diff --git a/pywr-core/src/parameters/profiles/uniform_drawdown.rs b/pywr-core/src/parameters/profiles/uniform_drawdown.rs
index bd8db084..fce5124b 100644
--- a/pywr-core/src/parameters/profiles/uniform_drawdown.rs
+++ b/pywr-core/src/parameters/profiles/uniform_drawdown.rs
@@ -46,7 +46,7 @@ impl SimpleParameter<f64> for UniformDrawdownProfileParameter {
         // Current calendar year (might be adjusted depending on position of reset day)
         let mut year = timestep.date.year();
 
-        // Zero-base current day of the year.
+        // Current day of the year.
         let current_doy = timestep.date.ordinal();
         let mut days_into_period: i32 = current_doy as i32 - self.reset_doy as i32;
         if days_into_period < 0 {
@@ -54,7 +54,7 @@ impl SimpleParameter<f64> for UniformDrawdownProfileParameter {
             year -= 1
         }
 
-        if self.reset_doy > 59 {
+        if self.reset_doy > 60 {
             year += 1
         }
 
@@ -66,8 +66,8 @@ impl SimpleParameter<f64> for UniformDrawdownProfileParameter {
         if days_into_period < 0 {
             days_into_period += 366;
             // Need to adjust for post 29th Feb in non-leap years.
-            // Recall `current_doy` was incremented by 1 if it is a non-leap already (hence comparison to 59)
-            if !is_leap_year(timestep.date.year()) && current_doy > 59 {
+            // Recall `current_doy` was incremented by 1 if it is a non-leap already (hence comparison to 60)
+            if !is_leap_year(timestep.date.year()) && current_doy > 60 {
                 days_into_period -= 1;
             }
         }