diff --git a/config/rel_slices.yml b/config/rel_slices.yml
index d2903542..ed898a70 100644
--- a/config/rel_slices.yml
+++ b/config/rel_slices.yml
@@ -587,6 +587,11 @@ m_bank_ovl.c:
     .rodata: [0x8064AE58, 0x8064AE90]
     .data: [0x806C7B90, 0x806C7BE0]
     .bss: [0x8133E0A8, 0x8133E0C0]
+m_birthday_ovl.c:
+    .text: [0x805C4714, 0x805C4E94]
+    .rodata: [0x8064AE90, 0x8064AEB8]
+    .data: [0x806C7BE0, 0x806C7C60]
+    .bss: [0x8133E0C0, 0x8133E0C8]
 m_editEndChk_ovl.c:
     .text: [0x805D7A64, 0x805D8498]
     .rodata: [0x8064B2C0, 0x8064B300]
diff --git a/include/m_birthday_ovl.h b/include/m_birthday_ovl.h
new file mode 100644
index 00000000..bf24014e
--- /dev/null
+++ b/include/m_birthday_ovl.h
@@ -0,0 +1,34 @@
+#ifndef M_BIRTHDAY_OVL_H
+#define M_BIRTHDAY_OVL_H
+
+#include "types.h"
+#include "m_birthday_ovl_h.h"
+#include "m_submenu_ovl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum {
+  mBR_Ovl_IDX_MONTH,
+  mBR_Ovl_IDX_DAY,
+  mBR_Ovl_IDX_DATE_NUM,
+
+  mBR_Ovl_IDX_OK = mBR_Ovl_IDX_DATE_NUM,
+  mBR_Ovl_IDX_NUM
+};
+
+struct birthday_ovl_s {
+  u16 birthday_data[mBR_Ovl_IDX_DATE_NUM];
+  int idx;
+};
+
+extern void mBR_birthday_ovl_set_proc(Submenu* submenu);
+extern void mBR_birthday_ovl_construct(Submenu* submenu);
+extern void mBR_birthday_ovl_destruct(Submenu* submenu);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/m_birthday_ovl_h.h b/include/m_birthday_ovl_h.h
new file mode 100644
index 00000000..13fd7224
--- /dev/null
+++ b/include/m_birthday_ovl_h.h
@@ -0,0 +1,16 @@
+#ifndef M_BIRTHDAY_OVL_H_H
+#define M_BIRTHDAY_OVL_H_H
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct birthday_ovl_s mBR_Ovl_c;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/m_submenu_ovl.h b/include/m_submenu_ovl.h
index 13edaac9..4099b0ce 100644
--- a/include/m_submenu_ovl.h
+++ b/include/m_submenu_ovl.h
@@ -23,6 +23,7 @@
 #include "m_timeIn_ovl_h.h"
 #include "m_repay_ovl_h.h"
 #include "m_notice_ovl_h.h"
+#include "m_birthday_ovl_h.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -139,7 +140,11 @@ struct submenu_overlay_s {
   /* 0x9B0 */ void* _9B0;
   /* 0x9B4 */ mMP_Overlay_c* map_ovl;
   /* 0x9B8 */ mNT_Ovl_c* notice_ovl;
-  /* 0x9BC */ u8 _9BC[0x9D0 - 0x9BC];
+  /* 0x9BC */ mBR_Ovl_c* birthday_ovl;
+  /* 0x9C0 */ void* _9C0;
+  /* 0x9C4 */ void* _9C4;
+  /* 0x9C8 */ void* _9C8;
+  /* 0x9CC */ void* _9CC;
   /* 0x9D0 */ mMU_Overlay_c* music_ovl;
   /* 0x9D4 */ mBN_Overlay_c* bank_ovl;
   /* 0x9D8 */ void* _9D8;
diff --git a/src/m_birthday_ovl.c b/src/m_birthday_ovl.c
new file mode 100644
index 00000000..a06db759
--- /dev/null
+++ b/src/m_birthday_ovl.c
@@ -0,0 +1,267 @@
+#include "m_birthday_ovl.h"
+
+#include "m_common_data.h"
+#include "m_font.h"
+#include "sys_matrix.h"
+
+static mBR_Ovl_c birthday_ovl_data;
+
+static void mBR_window_close(Submenu* submenu, mSM_MenuInfo_c* menu_info, mBR_Ovl_c* birthday_ovl) {
+  u16* data_p = birthday_ovl->birthday_data;
+
+  (*submenu->overlay->move_chg_base_proc)(menu_info, mSM_MOVE_OUT_TOP);
+  Common_Get(now_private)->birthday.month = data_p[mBR_Ovl_IDX_MONTH];
+  Common_Get(now_private)->birthday.day = data_p[mBR_Ovl_IDX_DAY];
+  sAdo_SysTrgStart(2);
+}
+
+static void mBR_move_Move(Submenu* submenu, mSM_MenuInfo_c* menu_info) {
+  (*submenu->overlay->move_Move_proc)(submenu, menu_info);
+}
+
+static void mBR_move_Play(Submenu* submenu, mSM_MenuInfo_c* menu_info) {
+  static lbRTC_time_c work_time = { 0, 0, 0, 1, lbRTC_SUNDAY, lbRTC_JANUARY, 2000 };
+  mBR_Ovl_c* birthday_ovl = submenu->overlay->birthday_ovl;
+  int* idx_p = &birthday_ovl->idx;
+  u16* data_p = birthday_ovl->birthday_data;
+  u32 trigger = submenu->overlay->menu_control.trigger;
+
+  if ((trigger & (BUTTON_B | BUTTON_CLEFT))) {
+    if (*idx_p != 0) {
+      (*idx_p)--;
+      sAdo_SysTrgStart(0x1003);
+    }
+  }
+  else if ((trigger & BUTTON_START)) {
+    mBR_window_close(submenu, menu_info, birthday_ovl);
+  }
+  else if ((trigger & (BUTTON_A | BUTTON_CRIGHT))) {
+    if (*idx_p == mBR_Ovl_IDX_OK) {
+      if ((trigger & BUTTON_CRIGHT) == 0) {
+        mBR_window_close(submenu, menu_info, birthday_ovl);
+      }
+    }
+    else {
+      (*idx_p)++;
+      sAdo_SysTrgStart(0xD);
+    }
+  }
+  else if ((trigger & (BUTTON_CUP | BUTTON_CDOWN))) {
+    if (*idx_p != mBR_Ovl_IDX_OK) {
+      if ((trigger & BUTTON_CDOWN)) {
+        data_p[*idx_p]--;
+      }
+      else {
+        data_p[*idx_p]++;
+      }
+
+      work_time.day = data_p[mBR_Ovl_IDX_DAY];
+      work_time.month = data_p[mBR_Ovl_IDX_MONTH];
+      if (!lbRTC_IsValidTime(&work_time)) {
+        if (
+          (
+            *idx_p == mBR_Ovl_IDX_MONTH &&
+            data_p[mBR_Ovl_IDX_MONTH] != 0 &&
+            data_p[mBR_Ovl_IDX_MONTH] < 13
+          ) || (
+            (trigger & BUTTON_CDOWN) &&
+            *idx_p == mBR_Ovl_IDX_DAY
+          )
+        ) {
+          work_time.day = 31;
+          while (!lbRTC_IsValidTime(&work_time)) {
+            work_time.day--;
+          }
+
+          data_p[mBR_Ovl_IDX_DAY] = work_time.day;
+        }
+        else if ((trigger & BUTTON_CUP)) {
+          data_p[*idx_p] = 1;
+        }
+        else {
+          data_p[mBR_Ovl_IDX_MONTH] = lbRTC_DECEMBER;
+        }
+      }
+
+      sAdo_SysTrgStart(1);
+    }
+  }
+}
+
+static void mBR_move_End(Submenu* submenu, mSM_MenuInfo_c* menu_info) {
+  (*submenu->overlay->move_End_proc)(submenu, menu_info);
+}
+
+typedef void (*mBR_OVL_MOVE_PROC)(Submenu*, mSM_MenuInfo_c*);
+
+static void mBR_birthday_ovl_move(Submenu* submenu) {
+  static mBR_OVL_MOVE_PROC ovl_move_proc[mSM_OVL_PROC_NUM] = {
+    &mBR_move_Move,
+    &mBR_move_Play,
+    (mBR_OVL_MOVE_PROC)none_proc1,
+    (mBR_OVL_MOVE_PROC)none_proc1,
+    &mBR_move_End
+  };
+
+  mSM_MenuInfo_c* menu_info = &submenu->overlay->menu_info[mSM_OVL_BIRTHDAY];
+
+  (*menu_info->pre_move_func)(submenu);
+  (*ovl_move_proc[menu_info->proc_status])(submenu, menu_info);
+}
+
+extern Gfx birthday_win_mode[];
+extern Gfx birthday_win_model[];
+extern Gfx brt_win_month_model[];
+
+extern u8 tim_win_january_tex_rgb_i4[];
+extern u8 tim_win_february_tex_rgb_i4[];
+extern u8 tim_win_march_tex_rgb_i4[];
+extern u8 tim_win_april_tex_rgb_i4[];
+extern u8 tim_win_may_tex_rgb_i4[];
+extern u8 tim_win_june_tex_rgb_i4[];
+extern u8 tim_win_july_tex_rgb_i4[];
+extern u8 tim_win_august_tex_rgb_i4[];
+extern u8 tim_win_september_tex_rgb_i4[];
+extern u8 tim_win_october_tex_rgb_i4[];
+extern u8 tim_win_november_tex_rgb_i4[];
+extern u8 tim_win_december_tex_rgb_i4[];
+
+static void mBR_set_dl(Submenu* submenu, mSM_MenuInfo_c* menu_info, GAME* game) {
+  static u8 chr_table[21] = "When's your birthday?";
+  static u8 close_table[2] = "OK";
+  static u8* month_tex[lbRTC_MONTHS_MAX] = {
+    tim_win_january_tex_rgb_i4,
+    tim_win_february_tex_rgb_i4,
+    tim_win_march_tex_rgb_i4,
+    tim_win_april_tex_rgb_i4,
+    tim_win_may_tex_rgb_i4,
+    tim_win_june_tex_rgb_i4,
+    tim_win_july_tex_rgb_i4,
+    tim_win_august_tex_rgb_i4,
+    tim_win_september_tex_rgb_i4,
+    tim_win_october_tex_rgb_i4,
+    tim_win_november_tex_rgb_i4,
+    tim_win_december_tex_rgb_i4
+  };
+  static int color_type[2][3] = {
+    { 195,   0,   0 },
+    {  70, 145, 225 }
+  };
+
+  GRAPH* graph = game->graph;
+  mBR_Ovl_c* birthday_ovl = submenu->overlay->birthday_ovl;
+  f32 x = menu_info->position[0];
+  f32 y = menu_info->position[1];
+  f32 tex_x;
+  f32 tex_y;
+  u8 str[2];
+  int* color_p;
+  u8 s;
+  u8 t;
+  Gfx* gfx;
+
+  Matrix_scale(16.0f, 16.0f, 1.0f, 0);
+  Matrix_translate(x, y, 140.0f, 1);
+
+  OPEN_DISP(graph);
+  gfx = NOW_POLY_OPA_DISP;
+
+  gSPMatrix(gfx++, _Matrix_to_Mtx_new(graph), G_MTX_NOPUSH | G_MTX_LOAD | G_MTX_MODELVIEW);
+  gSPDisplayList(gfx++, birthday_win_mode);
+  
+  tex_x = -submenu->overlay->menu_control.texture_pos[0] * 4.0f;
+  tex_y = -submenu->overlay->menu_control.texture_pos[1] * 4.0f;
+  s = (int)tex_x & 0xFF;
+  t = (int)tex_y & 0xFF;
+  gDPSetTileSize_Dolphin(gfx++, G_TX_RENDERTILE, s, t, 32, 32);
+  gSPDisplayList(gfx++, birthday_win_model);
+
+  color_p = color_type[birthday_ovl->idx != mBR_Ovl_IDX_MONTH];
+
+  gDPSetPrimColor(gfx++, 0, 255, color_p[0], color_p[1], color_p[2], 255);
+
+  gSPSegment(gfx++, G_MWO_SEGMENT_8, month_tex[birthday_ovl->birthday_data[mBR_Ovl_IDX_MONTH] - 1]);
+
+  gSPDisplayList(gfx++, brt_win_month_model);
+
+  SET_POLY_OPA_DISP(gfx);
+  CLOSE_DISP(graph);
+
+  (*submenu->overlay->set_char_matrix_proc)(graph);
+  mFont_SetLineStrings(
+    game,
+    chr_table, sizeof(chr_table),
+    x + 119.0f, -y + 88.0f,
+    255, 255, 255, 255,
+    FALSE,
+    TRUE,
+    0.875f, 0.875f,
+    mFont_MODE_POLY
+  );
+
+  mFont_UnintToString(str, 2, birthday_ovl->birthday_data[mBR_Ovl_IDX_DAY], 2, FALSE, TRUE, TRUE);
+
+  color_p = color_type[birthday_ovl->idx != mBR_Ovl_IDX_DAY];
+  mFont_SetLineStrings(
+    game,
+    str, sizeof(str),
+    x + 171.0f, -y + 124.0f,
+    color_p[0], color_p[1], color_p[2], 255,
+    FALSE,
+    TRUE,
+    1.0f, 1.0f,
+    mFont_MODE_POLY
+  );
+
+  color_p = color_type[birthday_ovl->idx != mBR_Ovl_IDX_OK];
+  mFont_SetLineStrings(
+    game,
+    close_table, sizeof(close_table),
+    x + 198.0f, -y + 124.0f,
+    color_p[0], color_p[1], color_p[2], 255,
+    FALSE,
+    TRUE,
+    1.0f, 1.0f,
+    mFont_MODE_POLY
+  );
+}
+
+static void mBR_birthday_ovl_draw(Submenu* submenu, GAME* game) {
+  mSM_MenuInfo_c* menu_info = &submenu->overlay->menu_info[mSM_OVL_BIRTHDAY];
+
+  (*menu_info->pre_draw_func)(submenu, game);
+  mBR_set_dl(submenu, menu_info, game);
+}
+
+extern void mBR_birthday_ovl_set_proc(Submenu* submenu) {
+  mSM_Control_c* control = &submenu->overlay->menu_control;
+
+  control->menu_move_func = &mBR_birthday_ovl_move;
+  control->menu_draw_func = &mBR_birthday_ovl_draw;
+}
+
+static void mBR_birthday_ovl_init(Submenu* submenu) {
+  mBR_Ovl_c* birthday_ovl = submenu->overlay->birthday_ovl;
+  (*submenu->overlay->move_chg_base_proc)(&submenu->overlay->menu_info[mSM_OVL_BIRTHDAY], mSM_MOVE_IN_TOP);
+  submenu->overlay->menu_control.animation_flag = FALSE;
+  
+  birthday_ovl->birthday_data[mBR_Ovl_IDX_MONTH] = lbRTC_JANUARY;
+  birthday_ovl->birthday_data[mBR_Ovl_IDX_DAY] = 1;
+  sAdo_SysTrgStart(0x17C);
+}
+
+extern void mBR_birthday_ovl_construct(Submenu* submenu) {
+  Submenu_Overlay_c* overlay = submenu->overlay;
+
+  if (overlay->birthday_ovl == NULL) {
+    mem_clear((u8*)&birthday_ovl_data, sizeof(mBR_Ovl_c), 0);
+    overlay->birthday_ovl = &birthday_ovl_data;
+  }
+
+  mBR_birthday_ovl_init(submenu);
+  mBR_birthday_ovl_set_proc(submenu);
+}
+
+extern void mBR_birthday_ovl_destruct(Submenu* submenu) {
+  submenu->overlay->birthday_ovl = NULL;
+}