This weekend we will be performing a routine server maintenance and upgrading of hardware on the API services environment for performance and scalability.
The maintenance will be performed July 28th 2018 starting from 10:00 AM (ET). We are expecting the entire process to take a few hours during which there might be intermittent connectivity issues to the Mainnet API services at https://etherscan.io/apis . All other services will not be effected. We will do our best to minimize the downtime by performing the upgrades in batches during the maintenance window.
If you have any questions please contact our support team at https://etherscan.io/contactus