How can i display rate alertview for every 30 days by using IRate Sdk

Question

I am showing the rate alert view in first 6 attempts and after that i need to display it on every 30 days using Irate SDK. how can i show that please help me.

  **First 6 attempts :**
[iRate sharedInstance].applicationBundleID = @"Bundle id";
        [iRate sharedInstance].onlyPromptIfLatestVersion = NO;
        [iRate sharedInstance].eventsUntilPrompt = 6;
        [iRate sharedInstance].daysUntilPrompt = 0;

  **to call for 30 days :**
[iRate sharedInstance].applicationBundleID = @"Bundle id";
    [iRate sharedInstance].onlyPromptIfLatestVersion = NO;
    [iRate sharedInstance].eventsUntilPrompt = 0;
    [iRate sharedInstance].daysUntilPrompt = 30;