Allow splitting 1945-48

src/NodaTimeSplitter.php

@@ -590,11 +590,19 @@ final class NodaTimeSplitter {
             return NodaSplitTime::genExactDate($year, $month, $day);
         }
         // Intl': 2020-12
-        if (\preg_match("/^[0-9]{4}\-[0-9]{2}$/", $datum)) { // German Y-m
+        if (\preg_match("/^[0-9]{4}\-[0-9]{2}$/", $datum)) { // German Y-m or 1912-15
             $year = \substr($datum, 0, 4);
             $month = \substr($datum, 5, 2);
+
+            // Assume the end is a month
+            if (intval($month) < 12) {
                 return new NodaSplitTime($year, $year, $month);
             }
+            else {
+                $end = \substr($year, 0, 2) . $month;
+                return new NodaSplitTime($year, $end);
+            }
+        }
 
         // German MM.JJJJ
         if (\preg_match("/^[0-9]{2}\.[0-9]{4}$/", $datum)) { // German Y-m

tests/NodaTimeSplitterTest.php

@@ -450,6 +450,19 @@ final class NodaTimeSplitterTest extends TestCase {
         self::assertEquals($output->toTimeName(), "1901-2000");
         self::assertEquals(NodaTimeSplitter::timePartsToCountingYear($output), 1951);
 
+        $output = NodaTimeSplitter::attempt_splitting("1945-48");
+        self::assertNotEmpty($output);
+        self::assertEquals($output->toOldFormat(), [
+            0 => "1945",
+            1 => "1948",
+            2 => "00",
+            3 => "00",
+            4 => "+",
+            5 => "",
+        ]);
+        self::assertEquals($output->toTimeName(), "1945-1948");
+        self::assertEquals(NodaTimeSplitter::timePartsToCountingYear($output), 1947);
+
         $output = NodaTimeSplitter::attempt_splitting("20.-19. Jahrhundert v. Chr.");
         self::assertNotEmpty($output);
         self::assertEquals($output->toOldFormat(), [