For those who don't know, today is National Pi Day (3/14). As a way of celebrating everyone's favorite irrational number, Microsoft is offering a 31.4 percent discount on Dell's XPS 13 2016 Edition laptop when bought from its store.

The Pi-based discount only applies to the entry-level Core i5 non-touch model, taking its price down to $685.31 from $999. Other XPS 13 variants are getting discounts of $200; this means you can get your hands on a top-end i7 model with 16GB of RAM for $1799 instead of $1999.

The 31.4 percent Pi Day discount is also being applied to Dell's Inspiron 13 2-in-1 and Inspiron 15 laptop, which will be available for $685.31 and $513.81 respectively. The three Pi discounts cover the Microsoft Signature Edition laptops, meaning they come with a reduced amount of bloatware.

Today also brings a promotion for the Raspberry Pi; anyone who buys a Raspberry Pi 2 Model B bundled with an 8GB MicroSD card will receive a free Pi 2 Power Supply.

In addition to the Pi Day discounts, Microsoft has now started its spring sale. Some of the offers include $100 off the 128GB and 256GB i5 versions of the Surface Pro 4, as well as money-off several other PCs, monitors, and accessories.

Those looking to pick up a Xbox One, meanwhile, will be able to get $100 off the Kinect bundle. There's also a deal where buyers of Microsoft's console will receive Grand Theft Auto V and another game free with select bundles.

The Pi deals are only for today, and the spring sale discounts will continue as long as stocks last.