moving ledger predictions to /ana

ana/window.go

@@ -0,0 +1,13 @@
+package ana
+
+import "time"
+
+func predictionTimes(window time.Duration) []time.Time {
+	result := []time.Time{}
+	last := time.Now()
+	for last.Before(time.Now().Add(window)) {
+		last = last.Add(-1 * time.Hour * 24 * time.Duration(last.Day())).Add(time.Hour * 24 * 33)
+		result = append(result, last)
+	}
+	return result
+}