diff --git a/internal/api/merch/helper.go b/internal/api/merch/helper.go
new file mode 100644
index 0000000..704cbbd
--- /dev/null
+++ b/internal/api/merch/helper.go
@@ -0,0 +1,19 @@
+package merch
+
+import (
+	"strconv"
+	"time"
+)
+
+func getPeriod(days string) time.Time {
+	daysInt, err := strconv.Atoi(days)
+	if err != nil {
+		daysInt = 7
+	}
+
+	if daysInt > 365 {
+		daysInt = 7
+	}
+
+	return time.Now().UTC().Add(-(time.Duration(daysInt) * time.Hour * 24))
+}