What would be the easiest way to use AWS to fire code at a certain date and time? Is it possible to use AWS Lambda, or would I need to create a web service in EC2? I prefer to use Xcode for iOS and if necessary Java using Eclipse and the AWS Toolkit and Elastic Beanstalk. I am creating an iOS app that fires remote notifications to the user at specified dates and time?
You can use AWS Lambda with a cloudwatch event schedule (either a rate like every 10 mins or a cron based schedule), it's all pretty easy to setup in the AWS console.
Lambda runtimes include: Node.js, Java, Python, and dotnet. The only thing you'd have to watch out for is your deployment package (code plus additional libraries) must be below 250Mb.
There are a few serverless frameworks (including one called Serverless) that can help setup and maintain projects, but for simple functions it's just as easy to write code directly in AWS console.