diff --git a/src/Concerns/Observable.php b/src/Concerns/Observable.php
index 52342c6fe..686c11b6d 100644
--- a/src/Concerns/Observable.php
+++ b/src/Concerns/Observable.php
@@ -43,8 +43,12 @@ protected function weekendToNextMonday(string|CarbonInterface $date, int $year):
         return null;
     }
 
-    protected function sundayToNextMonday(CarbonInterface $date): ?CarbonInterface
+    protected function sundayToNextMonday(string|CarbonInterface $date, int $year): ?CarbonInterface
     {
+        if (is_string($date)) {
+            $date = CarbonImmutable::createFromFormat('Y-m-d', "{$year}-{$date}")->startOfDay();
+        }
+
         if ($date->isSunday()) {
             return $date->next('monday');
         }
diff --git a/src/Countries/Jamaica.php b/src/Countries/Jamaica.php
index 801217120..96472e60f 100644
--- a/src/Countries/Jamaica.php
+++ b/src/Countries/Jamaica.php
@@ -4,9 +4,12 @@
 
 use Carbon\CarbonImmutable;
 use Carbon\CarbonInterface;
+use Spatie\Holidays\Concerns\Observable;
 
 class Jamaica extends Country
 {
+    use Observable;
+
     public function countryCode(): string
     {
         return 'jm';
@@ -33,7 +36,10 @@ protected function fixedHolidays(int $year): array
         ];
 
         foreach ($holidays as $name => $date) {
-            $observedDay = $this->observed($name, $date, $year);
+            $observedDay = match ($name) {
+                'Labour Day', 'Boxing Day' => $this->observed($name, $date, $year),
+                default => $this->sundayToNextMonday($date, $year),
+            };
 
             if ($observedDay) {
                 $holidays[$name.' Observed'] = $observedDay;
@@ -60,10 +66,6 @@ protected function observed(string $name, string $date, int $year): ?CarbonInter
     {
         $holiday = CarbonImmutable::createFromFormat('Y-m-d', "{$year}-{$date}")->startOfDay();
 
-        if ($holiday->isSunday()) {
-            return $holiday->next('monday');
-        }
-
         if ($name === 'Labour Day' && $holiday->isSaturday()) {
             return $holiday->next('monday');
         }
diff --git a/src/Countries/Latvia.php b/src/Countries/Latvia.php
index fb26ede73..ff6ac9346 100644
--- a/src/Countries/Latvia.php
+++ b/src/Countries/Latvia.php
@@ -3,9 +3,12 @@
 namespace Spatie\Holidays\Countries;
 
 use Carbon\CarbonImmutable;
+use Spatie\Holidays\Concerns\Observable;
 
 class Latvia extends Country
 {
+    use Observable;
+
     public function countryCode(): string
     {
         return 'lv';
@@ -45,20 +48,23 @@ protected function variableHolidays(int $year): array
     /** @return array<string, string> */
     protected function observedHolidays(int $year): array
     {
-        // If the holidays - May 4 and November 18 - fall on a Saturday or Sunday,
-        // the next working day is designated as a holiday.
-        $holidays = [];
+        $holidays = [
+            'Latvijas Republikas Neatkarības deklarācijas pasludināšanas diena' => '05-04',
+            'Latvijas Republikas proklamēšanas diena' => '11-18',
+        ];
 
-        $date = new CarbonImmutable();
+        foreach ($holidays as $name => $date) {
+            $observedDay = $this->weekendToNextMonday($date, $year);
 
-        $date = $date->setDate($year, 5, 4);
-        if ($date->isWeekend()) {
-            $holidays['Pārceltā 4. maija brīvdiena'] = $date->nextWeekday()->format('m-d');
-        }
+            if ($observedDay) {
+                if ($name === 'Latvijas Republikas Neatkarības deklarācijas pasludināšanas diena') {
+                    $holidays['Pārceltā 4. maija brīvdiena'] = $observedDay;
+                }
 
-        $date = $date->setDate($year, 11, 18);
-        if ($date->isWeekend()) {
-            $holidays['Pārceltā 18. novembra brīvdiena'] = $date->nextWeekday()->format('m-d');
+                if ($name === 'Latvijas Republikas proklamēšanas diena') {
+                    $holidays['Pārceltā 18. novembra brīvdiena'] = $observedDay;
+                }
+            }
         }
 
         return $holidays;
diff --git a/src/Countries/SouthAfrica.php b/src/Countries/SouthAfrica.php
index f85b14255..8ef21ac51 100644
--- a/src/Countries/SouthAfrica.php
+++ b/src/Countries/SouthAfrica.php
@@ -4,9 +4,12 @@
 
 use Carbon\CarbonImmutable;
 use Carbon\CarbonInterface;
+use Spatie\Holidays\Concerns\Observable;
 
 class SouthAfrica extends Country
 {
+    use Observable;
+
     public function countryCode(): string
     {
         return 'za';
@@ -30,7 +33,7 @@ protected function allHolidays(int $year): array
         ];
 
         foreach ($holidays as $name => $date) {
-            $observedDay = $this->observed($date, $year);
+            $observedDay = $this->sundayToNextMonday($date, $year);
 
             if ($observedDay) {
                 $holidays[$name.' Observed'] = $observedDay;
@@ -50,16 +53,4 @@ protected function variableHolidays(int $year): array
             'Family Day' => $easter->addDay(),
         ];
     }
-
-    protected function observed(string $date, int $year): ?CarbonInterface
-    {
-        $holiday = CarbonImmutable::createFromFormat('Y-m-d', "{$year}-{$date}")->startOfDay();
-
-        // https://www.gov.za/documents/public-holidays-act
-        if ($holiday->isSunday()) {
-            return $holiday->next('monday');
-        }
-
-        return null;
-    }
 }