diff --git a/main.go b/main.go
index 20287cd..36d5989 100644
--- a/main.go
+++ b/main.go
@@ -5,6 +5,8 @@ import (
 	"net/http"
 	"strings"
 	"os"
+	"context"
+	"time"
 )
 
 // ELIGIBLE_APPOINTMENTS is a comma-separated list of appointment type
@@ -57,6 +59,26 @@ func main() {
 	}
 
 	srv := NewServer(NewClient(apiKey, dryRun), store, secret, loadEligible())
+	// Prime the cache: a fresh container starts empty.
+	{
+		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Minute)
+		if err := srv.SyncRoster(ctx); err != nil {
+			log.Printf("initial sync failed: %v", err)
+		}
+		cancel()
+	}
+
+	go func() {
+		t := time.NewTicker(time.Hour)
+		defer t.Stop()
+		for range t.C {
+			ctx, cancel := context.WithTimeout(context.Background(), 15*time.Minute)
+			if err := srv.SyncRoster(ctx); err != nil {
+				log.Printf("scheduled sync failed: %v", err)
+			}
+			cancel()
+		}
+	}()
 	log.Println("listening on :8080")
 	log.Fatal(http.ListenAndServe(":8080", srv.Routes()))
 }