diff --git a/src/lib/gcloud.ts b/src/lib/gcloud.ts
index 290545b..6d47c92 100644
--- a/src/lib/gcloud.ts
+++ b/src/lib/gcloud.ts
@@ -273,6 +273,7 @@ export async function exportParticipants({
         if (userParticipation.role === "CONTESTANT") {
           data = {
             ...data,
+            "Fecha de registro": `=DATEVALUE(MID("${participation.registeredAt}",1,10))+TIMEVALUE(MID("${participation.registeredAt}",12,8))`,
             Estado: userParticipation.schoolState,
             Escuela: userParticipation.schoolName.trim(),
           };
diff --git a/src/lib/ofmi.ts b/src/lib/ofmi.ts
index 026d7fd..350bc9a 100644
--- a/src/lib/ofmi.ts
+++ b/src/lib/ofmi.ts
@@ -118,6 +118,7 @@ export async function findParticipants(
           references: mailingAddress.references ?? undefined,
         },
       },
+      registeredAt: participation.createdAt,
       userParticipation: userParticipation as UserParticipation,
     };
 
@@ -201,6 +202,7 @@ export async function findParticipation(
         references: mailingAddress.references ?? undefined,
       },
     },
+    registeredAt: participation.createdAt,
     userParticipation: userParticipation as UserParticipation,
   };
 
diff --git a/src/types/participation.schema.ts b/src/types/participation.schema.ts
index 7e25f71..464cc1e 100644
--- a/src/types/participation.schema.ts
+++ b/src/types/participation.schema.ts
@@ -109,13 +109,17 @@ export type ParticipationRequestInput = Static<
 export const ParticipationRequestInputSchema = Type.Object({
   ofmiEdition: Type.Integer({ minimum: 1 }),
   user: UserInputSchema,
+  registeredAt: Type.Date(),
   userParticipation: UserParticipationSchema,
 });
 
 export type UpsertParticipationRequest = Static<
   typeof UpsertParticipationRequestSchema
 >;
-export const UpsertParticipationRequestSchema = ParticipationRequestInputSchema;
+export const UpsertParticipationRequestSchema = Type.Omit(
+  ParticipationRequestInputSchema,
+  ["registeredAt"],
+);
 
 export interface UpsertParticipationResponse {
   participation: Participation;