diff --git a/include/grpc/census.h b/include/grpc/census.h
index 591d0dc52b7..ef6275fe58d 100644
--- a/include/grpc/census.h
+++ b/include/grpc/census.h
@@ -129,10 +129,14 @@ void census_set_trace_mask(int trace_mask);
    each logical operation. */
 
 /**
-  This structure (opaquely) represents a timestamp as used by census to
-  record the time at which an RPC operation begins.
+  This structure represents a timestamp as used by census to record the time
+  at which an operation begins.
 */
-typedef struct census_timestamp census_timestamp;
+typedef struct {
+  /* Use gpr_timespec for default implementation. High performance
+   * implementations should use a cycle-counter based timestamp. */
+  gpr_timespec ts;
+} census_timestamp;
 
 /**
   Mark the beginning of an RPC operation. The information required to call the
@@ -148,7 +152,7 @@ typedef struct census_timestamp census_timestamp;
 
   @return A timestamp representing the operation start time.
 */
-census_timestamp *census_start_rpc_op_timestamp(void);
+census_timestamp census_start_rpc_op_timestamp(void);
 
 /**
   Represent functions to map RPC name ID to service/method names. Census
diff --git a/src/core/census/operation.c b/src/core/census/operation.c
index a0196da6146..118eb0a47ad 100644
--- a/src/core/census/operation.c
+++ b/src/core/census/operation.c
@@ -34,7 +34,13 @@
 
 /* TODO(aveitch): These are all placeholder implementations. */
 
-census_timestamp *census_start_rpc_op_timestamp(void) { return NULL; }
+census_timestamp census_start_rpc_op_timestamp(void) {
+  census_timestamp ct;
+  /* TODO(aveitch): assumes gpr_timespec implementation of census_timestamp. */
+  ct.ts = gpr_now(GPR_CLOCK_MONOTONIC);
+  return ct;
+}
+
 census_context *census_start_client_rpc_op(
     const census_context *context, gpr_int64 rpc_name_id,
     const census_rpc_name_info *rpc_name_info, const char *peer, int trace_mask,