There are two Bands called Seize the Day.
Seize the Day from Switzerland is a young metalcore screamo Band from Zurich, Switzerland.
Seize the Day from Britain is a folk band, and their music has strong environmentalist and political themes. More information is available at the band's website http://www.seizetheday.org/.
Albums include All Hands That Are Ready, The Tide Is Turning, Alive, and PondLife Primer.

The band was founded by singer-songwriters Theo Simon and Shannon Smy in 1997, but is now a 5-8 piece acoustic band, which play every year at the Glastonbury Festival, as well as many other folk festivals, as well as touring around the world
Their activist songs have often led them into controversy, for example: they won the BBC Radio 3 audience poll for the World Music Awards, but were denied the award due to their songs that opposed the war in Iraq. Band members can also be found at protests and demonstrations, such as those against GM crops and the construction of new nuclear power plants.