Day started his career at Tottenham Hotspur, where he spent five years, making one Premier League appearance for the North London club.

He was released by Lincoln, and later joined Queens Park Rangers, spending three and a half years at the club, whilst also having brief spells on loan at Aylesbury United and Preston North End.

[5] Ahead of the 1995–96 season, Day played in all four of Tottenham's UEFA Intertoto Cup group games, with the club fielding a weakened team in the competition.

[19] He played his last game for Watford in a 1–0 victory over Coventry City in May 2000,[20] as the signing of Espen Baardsen in the summer of 2000 meant Day became third-choice goalkeeper.

Shortly after, Day suffered a broken leg in a home game against Oldham Athletic after a challenge with striker Matthew Tipton.

[27][28] As part of his lengthy recovery plan, he was loaned to non-League Aylesbury United in October 2002,[29] and made his debut for the club in a 0–0 home draw against Harrow Borough.

Day was an unused substitute in QPR's 3–1 win against Sheffield Wednesday, a victory that ultimately secured automatic promotion back to the Championship.

[36] He was dropped in January 2005 in favour of loanee Simon Royce, and was, as a result, allowed to move to Preston North End on a one-month loan deal.

[37] He made his Preston debut in a 2–0 defeat to Nottingham Forest,[38] as well as making five more appearances for the Lancashire club; keeping two clean sheets during his time there.

[39] Having played two more games for QPR on his return, Day was allowed to leave for Oldham Athletic a week before the start of the 2005–06 season.

[42] Then manager Ronnie Moore took the opportunity to sign out of favour Derby County goalkeeper Lee Grant on loan at the end of the January transfer window, and Day subsequently became second-choice for the remainder of the season.

[46] He regained his place as first-choice goalkeeper for the start of Millwall's league season; keeping two clean sheets in his first two games.

[55] He also started in six of the club's FA Trophy campaign during that season, keeping four clean sheets and playing in the side's 2–0 win against York City in the final at Wembley Stadium.

[64] He helped Stevenage earn their first away point of the season in a 1–1 draw at Aldershot Town, saving Marvin Morgan's 86th-minute penalty to keep the scores tied.

[66][67] Stevenage earned promotion to League One after a 1–0 victory against Torquay United at Old Trafford on 28 May 2011, with Day playing the whole game and keeping a clean sheet.

[73] Day made his first appearance of the campaign on 16 August 2011, playing the whole game in Stevenage's first win of season, a 3–1 away victory at AFC Bournemouth.

[76] Stevenage's FA Cup run to the Fifth Round also presented Day with the opportunity to face his former club, and the team he supports, Tottenham Hotspur.

[86][87] Despite the club being unbeaten in their first nine league games with Day in goal, he was dropped by manager Gary Smith in favour of pre-season signing Steve Arnold following Stevenage's 2–2 draw with Bury on 29 September 2012.

[88] He was subsequently second-choice goalkeeper for most of the remainder of the season, although briefly returned to first-team action after Arnold had been unavailable due to suspension.

[89] Following the return of manager Graham Westley, who brought Day to the club in August 2008, he ended the season by playing in Stevenage's remaining two league fixtures.