Amazon Exam AWS-Certified-Solutions-Architect-Professional Topic 1 Question 2 Discussion

You can publish your own metrics to CloudWatch with the put-metric-data command (or its Query API equivalent PutMetricData). When you create a new metric using the put-metric-data command, it can take up to two minutes before you can retrieve statistics on the new metric using the get-metric-statistics command. However, it can take up to fifteen minutes before the new metric appears in the list of metrics retrieved using the list-metrics command.

http://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/publishingMetrics.html