1 files changed, 2 insertions, 2 deletions
diff --git a/src/lib.rs b/src/lib.rs
index 39f225f..0f2c597 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -251,8 +251,8 @@ impl SimUpdates {
             update,
         } in periodic.iter()
         {
-            let base = from.unwrap_or(0);
-            if month % period == base && base <= month && to.unwrap_or(month + 1) > month {
+            let base = from.unwrap_or(1);
+            if (month - base) % period == 0 && base <= month && to.unwrap_or(month) >= month {
                 ret.push(*update);
             }
         }