"This Is the Day" is a song written by Matt Johnson and originally released as a single by his band The The on 2 September 1983.

[4] A version of the song was included on the band's debut album Soul Mining, released in October 1983.

A re-recorded version of the song, re-titled "That Was the Day", was released as the lead track on the Dis-Infected EP in 1993.

Credits for the album version are adapted from the sleeve notes for Soul Mining.

The CD single was only available as a limited edition with the CD/DVD version of National Treasures on the HMV website.