WhatsApp is a greedy application, likes to take over control of your SIM card and phone number (albeit for logical reasons) and also needs a little control over when it's allowed to run, check for new messages and so on. WhatsApp Scheduler is a recently updated utility that provides just this control, with the only caveat being that this is part of the brave new world of applications outside the cosy Nokia Store - and, with this being quite a low level utility, it needs permissions and it comes 'unsigned'. You'll need custom firmware or similar to be able to install this successfully.

From the developer's description:

WA Scheduler periodically starts and stops WhatsApp to check for new messages. You only need to set the days and hours you want sync in, then select an update frequency. By running in background you can get message notifications from WhatsApp without being always connected.

Some screens, again courtesy of the developer:

Configuring WhatsApp Scheduler, setting WhatsApp for daytime operation on workdays only....

There's a full changelog for recent versions and a download link here.

This could turn into a bit of a FAQ for this and future news and 'flow' items on AAS, but in order to install this you'll need to be running custom firmware and with the InstallServer patch active (as far as I know - clarifications welcome in the comments), or similar. If you're not sure if your device can install 'unsigned' applications then you almost certainly can't!

If you're a newbie to custom firmwares, check out some of my Delight adventures, e.g. here.

Also, WhatsApp itself isn't in the (frozen) Nokia Store, so download it here.