diff --git a/packages/tendermint-rpc/src/dates.spec.ts b/packages/tendermint-rpc/src/dates.spec.ts
index e1e2a496..a9883af4 100644
--- a/packages/tendermint-rpc/src/dates.spec.ts
+++ b/packages/tendermint-rpc/src/dates.spec.ts
@@ -1,6 +1,12 @@
 import { ReadonlyDate } from "readonly-date";
 
-import { DateTime, DateWithNanoseconds, fromRfc3339WithNanoseconds, toRfc3339WithNanoseconds } from "./dates";
+import {
+  DateTime,
+  DateWithNanoseconds,
+  fromRfc3339WithNanoseconds,
+  toRfc3339WithNanoseconds,
+  toSeconds,
+} from "./dates";
 
 describe("dates", () => {
   describe("fromRfc3339WithNanoseconds", () => {
@@ -55,6 +61,51 @@ describe("dates", () => {
     });
   });
 
+  describe("toSeconds", () => {
+    it("works", () => {
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26Z");
+        expect(toSeconds(date)).toEqual([1608029846, 0]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.7Z");
+        expect(toSeconds(date)).toEqual([1608029846, 700000000]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.77Z");
+        expect(toSeconds(date)).toEqual([1608029846, 770000000]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.778Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778000000]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.7789Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778900000]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.77809Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778090000]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.778009Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778009000]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.7780009Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778000900]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.77800009Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778000090]);
+      }
+      {
+        const date = fromRfc3339WithNanoseconds("2020-12-15T10:57:26.778000009Z");
+        expect(toSeconds(date)).toEqual([1608029846, 778000009]);
+      }
+    });
+  });
+
   describe("DateTime", () => {
     it("decodes a string", () => {
       expect(DateTime.decode("2020-12-15T10:57:26.778Z").nanoseconds).toEqual(0);
diff --git a/packages/tendermint-rpc/src/dates.ts b/packages/tendermint-rpc/src/dates.ts
index 4a15ccfc..c296e1b1 100644
--- a/packages/tendermint-rpc/src/dates.ts
+++ b/packages/tendermint-rpc/src/dates.ts
@@ -25,6 +25,19 @@ export function toRfc3339WithNanoseconds(dateTime: ReadonlyDateWithNanoseconds):
   return `${millisecondIso.slice(0, -1)}${nanoseconds.padStart(6, "0")}Z`;
 }
 
+/**
+ * Caclulates the UNIX timestamp in seconds as well as the nanoseconds after the given second.
+ *
+ * This is useful when dealing with external systems like the protobuf type
+ * [.google.protobuf.Timestamp](https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#google.protobuf.Timestamp)
+ * or any other system that does not use millisecond precision.
+ */
+export function toSeconds(date: ReadonlyDateWithNanoseconds): [number, number] {
+  const seconds = Math.floor(date.getTime() / 1000);
+  const nanos = (date.getTime() % 1000) * 1000000 + (date.nanoseconds ?? 0);
+  return [seconds, nanos];
+}
+
 /** @deprecated Use fromRfc3339WithNanoseconds/toRfc3339WithNanoseconds instead */
 export class DateTime {
   /** @deprecated Use fromRfc3339WithNanoseconds instead */
diff --git a/packages/tendermint-rpc/src/index.ts b/packages/tendermint-rpc/src/index.ts
index c6584a41..5864129f 100644
--- a/packages/tendermint-rpc/src/index.ts
+++ b/packages/tendermint-rpc/src/index.ts
@@ -6,6 +6,7 @@ export {
   ReadonlyDateWithNanoseconds,
   fromRfc3339WithNanoseconds,
   toRfc3339WithNanoseconds,
+  toSeconds,
 } from "./dates";
 export {
   AbciInfoRequest,