Ends 8.00.

The Silver Brumby
A fall of snow hits the high country. (R)(S)

6.25 UBOS
Cassy "shifts" into Zarlak's shape during a fight in the world of imps. (R)(S)

6.45 Dennis the Menace
Aliens arrive from outerspace. (R)(S)

7.10 ChuckleVision
Paul and Barry track down a microchip. (R)(S)

7.30 Blue Peter
Celebrating two 50th anniversaries - one athletic, the other musical. Busted perform live.
(Shown yesterday 5pm BBC1) (S)

7.55 Newsround (S)

Ends 10.30.

Big Cook, Little Cook
Ben and Small make some jazzy ice cream for Rocking Raymond.

8.20 Tots TV
Tom makes a magical hat which, when caught by the wind, ends up in a tree.

8.30 Bobinogs
Dylan the dragon does not make a good pet.
First shown on BBC Wales

8 45 Boo!
A big pond provides a place for Boo to hide.

9.00 Balamory
Archie has created an invention - it's called a noisy hat.
Cast on Wednesday BBC1

9.20 SMarteenies
More examples of pattern design, another big picture, plus a look at the gallery.

Followed by CBeebies Birthdays

9.40 Tweenies
The friends dress up as sea creatures.

10.00 Teletubbies
A pair of mittens materialise.
BBC products: Teletubbies: Again Again! video £7.99, DVD £10.99

Repeats are not indicated.
10.30 BBC Primary Geography (ages 7-11) Postcards - Kenya:
Introduction to Kenya
10.40 BBC Primary Geography
(ages 7-11) Postcards - France: Paris 1114640 10.50 Look and Read (ages 7- 9) Spelling with the Spellits Year 3/4 (Programme 2)
11.10 Megamaths(ages7-9)
Division - Divide by Two

The latest developments at Westminster.

Business news, plus another report on British entrepreneurs in Latvia and Lithuania, aiming to cash in as ten new countries join the European Union.

Repeats are not indicated.
1.00 Numbertime (ages 4-6) More or Less - One More
1.15 Words and Pictures Plus
(ages 6-7) Long Vowel Spelling - Mr McGhee Goes to the Sea "ee/ea"

Live coverage of the world championship quarter- finals from the Crucible Theatre.
At this stage last year
Stephen Lee reached the semi-finals for the first time with a 13-7 win over Marco Fu. He was, however, given short shrift in the next round by the eventual champion Mark Williams 17-8.
Introduced by Hazel Irvine , with Steve Davis and John Parrott. Ray Edmonds ,
Clive Everton , Terry Griffiths , Dennis Taylor , Willie Thorne and John Virgo provide the commentary. www.bbc.co.uk/snooker BBCi: from 10am digital viewers can access live coverage of both tables, plus a news and statistics service, via the red button on their handset

Double bill of the American sitcom starring Will Smith. Stop Will! in the Name of Love. Will is overprotective while chaperoning Ashley on her date.
6.25 You'd Better Shop Around. Will quits university to become a successful car salesman.

Sheffield's Crucible Theatre hosts action from the quarter-finals of the world championship, where the difference between winning and losing is a hefty £31,600.
At this stage last year, England's Paul Hunter claimed a semi-final place after sealing a thrilling 13-12 win over compatriot Peter Ebdon. The defending champion had edged into a 10-9 lead but Hunter refused to crack, securing the next three frames to put himself in touching distance of victory. Ebdon's resilience ensured that the match would go to a tension-filled decider, yet on this occasion the more experienced player fell at the final hurdle. Welshman Mark Williams had no such trouble reaching the semi-finals: the 2000 world champion's impressive 13-7 victory over Stephen Hendry meant that he became only the second player to regain the world number-one ranking, a feat first accomplished by fellow countryman Ray Reardon.
Presented by Ray Stubbs , with analysis from
Steve Davis and John Parrott. Commentary comes from Ray Edmonds , Clive Everton , Terry Griffiths , Dennis Taylor ,
Willie Thorne and John Virgo. BBCi: digital viewers can access extra live coverage of both tables, plus a news and statistics service, via the red button on their handset

New series 1/5. In competition, does gardener Diarmuid Gavin harbour a burning desire to come out on top or is it just the taking part that really matters to him? See for yourself as cameras follow the horticulturalist at home, work and play over a period of nine months as he creates a show-garden to rival his competitors at this year's Chelsea Flower Show. It's his biggest challenge to date, but surely an achievable one for the gardener who shot to fame as a presenter on Home Front, fashioning inspirational gardens that were either loved or loathed. He could be about to teach the experts a lesson or two - yet it might all end in tears.
Series producer Steve Greenwood ; Executive producer Julian Mercer Diarmuid takes on the might of Chelsea: page 36

On day 11 of the tournament, Ray Stubbs introduces highlights from tonight's quarter-finals at the Crucible Theatre, Sheffield. Matches are the best of 25 frames, played over three sessions. With analysis from
Steve Davis and John Parrott. BBCi: digital viewers can access extra live coverage of both tables, plus a news and statistics service, via the red button on their handset

In-depth analysis of the day's top news stories, presented by Jeremy Paxman.

Highlights from tonight's quarter-final matches in Sheffield. Presented by Ray Stubbs.

BBCi: digital viewers can access extra live coverage of both tables, plus a news and statistics service, via the red button on their handset

Hazel Irvine introduces further highlights of the day's quarter-final matches in the world championship.

www.bbc.co.uk/learningzone
Schools Repeats are not indicated.
2.00 GSCE Bltesize Revision Design and Technology 1. How to create products effectively, with reference to graphic products and food technology. 14867 4.00 GCSE Biteslze Revision Design and Technology 2. A look at resistant materials, systems and controls, and electronic products and textiles.