Today a new version of timed-themes vscode extension was released and published to the vscode marketplace. Timed themes switches between a dark and light theme based on a schedule. The schedule can be set using time ranges in the settings. The dark and light themes are also configurable. Version 0.3.0 includes two minor bug fixes as well as package updates to the dependencies.

Here's the link to the extension at the vscode marketplace - Timed Themes