diff --git a/AK/Time.h b/AK/Time.h
index 9a87f3c389..f70b6f828d 100644
--- a/AK/Time.h
+++ b/AK/Time.h
@@ -43,13 +43,18 @@ inline bool is_leap_year(int year)
     return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
 }
 
+inline unsigned days_in_year(int year)
+{
+    return 365 + is_leap_year(year);
+}
+
 inline int years_to_days_since_epoch(int year)
 {
     int days = 0;
     for (int current_year = 1970; current_year < year; ++current_year)
-        days += 365 + is_leap_year(current_year);
+        days += days_in_year(current_year);
     for (int current_year = year; current_year < 1970; ++current_year)
-        days -= 365 + is_leap_year(current_year);
+        days -= days_in_year(current_year);
     return days;
 }
 
@@ -173,6 +178,7 @@ inline bool operator!=(const TimespecType& a, const TimespecType& b)
 
 using AK::day_of_year;
 using AK::days_in_month;
+using AK::days_in_year;
 using AK::is_leap_year;
 using AK::timespec_add;
 using AK::timespec_add_timeval;
diff --git a/Libraries/LibC/time.cpp b/Libraries/LibC/time.cpp
index 7d35a4e3f4..01f7a164f0 100644
--- a/Libraries/LibC/time.cpp
+++ b/Libraries/LibC/time.cpp
@@ -70,10 +70,10 @@ static void time_to_tm(struct tm* tm, time_t t)
     tm->tm_wday /= __seconds_per_day;
 
     int year = 1970;
-    for (; t >= (365 + is_leap_year(year)) * __seconds_per_day; ++year)
-        t -= (365 + is_leap_year(year)) * __seconds_per_day;
+    for (; t >= days_in_year(year) * __seconds_per_day; ++year)
+        t -= days_in_year(year) * __seconds_per_day;
     for (; t < 0; --year)
-        t += (365 + is_leap_year(year - 1)) * __seconds_per_day;
+        t += days_in_year(year - 1) * __seconds_per_day;
     ASSERT(t >= 0);
 
     int days = t / __seconds_per_day;
@@ -275,7 +275,7 @@ size_t strftime(char* destination, size_t max_size, const char* format, const st
                     if (tm->tm_yday >= 7 - wday_of_year_beginning)
                         --week_number;
                     else {
-                        const int days_of_last_year = 365 + is_leap_year(tm->tm_year + 1900 - 1);
+                        const int days_of_last_year = days_in_year(tm->tm_year + 1900 - 1);
                         const int wday_of_last_year_beginning = (wday_of_year_beginning + 6 * days_of_last_year) % 7;
                         week_number = (days_of_last_year + wday_of_last_year_beginning) / 7 + 1;
                         if (wday_of_last_year_beginning > 3)
diff --git a/Libraries/LibCore/DateTime.cpp b/Libraries/LibCore/DateTime.cpp
index e0dba3493e..d632e321da 100644
--- a/Libraries/LibCore/DateTime.cpp
+++ b/Libraries/LibCore/DateTime.cpp
@@ -216,8 +216,7 @@ String DateTime::to_string(const String& format) const
                     if (tm.tm_yday >= 7 - wday_of_year_beginning)
                         --week_number;
                     else {
-                        const bool last_year_is_leap = ::is_leap_year(tm.tm_year + 1900 - 1);
-                        const int days_of_last_year = 365 + last_year_is_leap;
+                        const int days_of_last_year = days_in_year(tm.tm_year + 1900 - 1);
                         const int wday_of_last_year_beginning = (wday_of_year_beginning + 6 * days_of_last_year) % 7;
                         week_number = (days_of_last_year + wday_of_last_year_beginning) / 7 + 1;
                         if (wday_of_last_year_beginning > 3)