diff --git a/app/components/dashboard/header.tsx b/app/components/dashboard/header.tsx
index d8e350f..b458b6b 100644
--- a/app/components/dashboard/header.tsx
+++ b/app/components/dashboard/header.tsx
@@ -104,31 +104,26 @@ export function Header({
     }
   };
 
-  const nextFromYearHandler = () => {
-    if (currentYear && (currentYear.since ?? 0) < (currentYear.until ?? 0)) {
-      const data = {
-        ...currentYear,
-        since: currentYear.since! + 1,
-      };
-      setCurrentYear(data);
-      EventBus.emit("dateSelected", {
-        ...selectedDate,
-        start: `${data.since}/${selectedDate.start?.split("/").slice(1).join("/")}`,
-      });
-    }
+  const changeSinceYear = (delta: number) => {
+    if (!currentYear) return;
+
+    const newSince = (currentYear.since ?? 0) + delta;
+
+    if (newSince > (currentYear.until ?? Infinity) || newSince < 0) return;
+
+    const updatedYear = { ...currentYear, since: newSince };
+    setCurrentYear(updatedYear);
+
+    const updatedDate = {
+      ...selectedDate,
+      start: `${newSince}/${selectedDate.start?.split("/").slice(1).join("/")}`,
+    };
+    setSelectedDate(updatedDate);
+    EventBus.emit("dateSelected", updatedDate);
   };
 
-  const prevFromYearHandler = () => {
-    const data = {
-      ...currentYear,
-      since: currentYear.since! - 1,
-    };
-    setCurrentYear(data);
-    EventBus.emit("dateSelected", {
-      ...selectedDate,
-      start: `${data.since}/${selectedDate.start?.split("/").slice(1).join("/")}`,
-    });
-  };
+  const nextFromYearHandler = () => changeSinceYear(1);
+  const prevFromYearHandler = () => changeSinceYear(-1);
 
   const selectFromDateHandler = (val: MonthItem) => {
     const data = {
@@ -140,31 +135,26 @@ export function Header({
     EventBus.emit("dateSelected", data);
   };
 
-  const nextUntilYearHandler = () => {
-    const data = {
-      ...currentYear,
-      until: currentYear.until! + 1,
-    };
-    setCurrentYear(data);
-    EventBus.emit("dateSelected", {
+  const changeUntilYear = (delta: number) => {
+    if (!currentYear) return;
+
+    const newUntil = (currentYear.until ?? 0) + delta;
+
+    if (newUntil < (currentYear.since ?? 0)) return;
+
+    const updatedYear = { ...currentYear, until: newUntil };
+    setCurrentYear(updatedYear);
+
+    const updatedDate = {
       ...selectedDate,
-      end: `${data.until}/${selectedDate?.end?.split("/").slice(1).join("/")}`,
-    });
+      end: `${newUntil}/${selectedDate.end?.split("/").slice(1).join("/")}`,
+    };
+    setSelectedDate(updatedDate);
+    EventBus.emit("dateSelected", updatedDate);
   };
 
-  const prevUntilYearHandler = () => {
-    if (currentYear && (currentYear.since ?? 0) < (currentYear.until ?? 0)) {
-      const data = {
-        ...currentYear,
-        until: currentYear.until! - 1,
-      };
-      setCurrentYear(data);
-      EventBus.emit("dateSelected", {
-        ...selectedDate,
-        end: `${data.until}/${selectedDate.end?.split("/").slice(1).join("/")}`,
-      });
-    }
-  };
+  const nextUntilYearHandler = () => changeUntilYear(1);
+  const prevUntilYearHandler = () => changeUntilYear(-1);
 
   const selectUntilDateHandler = (val: MonthItem) => {
     const data = {