diff --git a/src/main/java/com/ffii/fpsms/modules/report/service/StockLotLedgerReportService.kt b/src/main/java/com/ffii/fpsms/modules/report/service/StockLotLedgerReportService.kt
index 16547fce..1166a127 100644
--- a/src/main/java/com/ffii/fpsms/modules/report/service/StockLotLedgerReportService.kt
+++ b/src/main/java/com/ffii/fpsms/modules/report/service/StockLotLedgerReportService.kt
@@ -46,6 +46,22 @@ open class StockLotLedgerReportService(
         return LedgerPeriod(start = startParsed.withDayOfMonth(1), end = end)
     }
 
+    /** First day of the earliest month that has a stock_ledger row. */
+    fun earliestLedgerMonth(): LocalDate {
+        val row = jdbcDao.queryForList(
+            """
+            SELECT DATE_FORMAT(MIN(sl.date), '%Y-%m-%d') AS firstDate
+            FROM stock_ledger sl
+            WHERE sl.deleted = 0
+            """.trimIndent(),
+            emptyMap<String, Any>(),
+        ).firstOrNull()
+        val raw = row?.get("firstDate")?.toString()?.trim().orEmpty()
+        val parsed = raw.takeIf { it.isNotEmpty() && !it.equals("null", ignoreCase = true) }
+            ?.let { runCatching { LocalDate.parse(it.take(10)) }.getOrNull() }
+        return (parsed ?: LocalDate.now()).withDayOfMonth(1)
+    }
+
     fun searchStockLotLedgerReport(
         itemCode: String?,
         reportPeriodStart: String?,
diff --git a/src/main/java/com/ffii/fpsms/modules/report/web/StockLotLedgerReportController.kt b/src/main/java/com/ffii/fpsms/modules/report/web/StockLotLedgerReportController.kt
index d8ac95da..cea09dc4 100644
--- a/src/main/java/com/ffii/fpsms/modules/report/web/StockLotLedgerReportController.kt
+++ b/src/main/java/com/ffii/fpsms/modules/report/web/StockLotLedgerReportController.kt
@@ -47,6 +47,12 @@ class StockLotLedgerReportController(
         val dash: CellStyle,
     )
 
+    @GetMapping("/stock-lot-ledger-earliest")
+    fun earliestLedgerMonth(): Map<String, String> {
+        val earliest = stockLotLedgerReportService.earliestLedgerMonth()
+        return mapOf("earliest" to earliest.format(DateTimeFormatter.ISO_LOCAL_DATE))
+    }
+
     @GetMapping("/print-stock-lot-ledger-excel")
     fun exportStockLotLedgerReportExcel(
         @RequestParam(required = false) itemCode: String?,