If skies are blue...
Walk: an hour before sunset (it is at 7.30 approximately) get your trainers on then go power-walking (taking big steps and pumping your arms by your sides) for half-an-hour. Stop, turn around and power-walk back home again.
Fly a kite: spend 25 minutes making a kite using a plastic bag, wood and string, then visit your park and spend 35 minutes getting frustrated because you can't make it fly. Alternatively visit the Kite Store (48 Neal Street, London WC2) and buy a kite, then spend an hour getting frustrated because you can't make it fly.
Time freeze: go to Greenwich Park and escape from BST by visiting the Old Royal Observatory, where all the clocks are kept on GMT. Or stand on the prime meridian, the brass line that marks GMT, and be one hour behind everyone else.
Tower it: climb to the top of Blackpool Tower and see the Isle of Man. The tower is nearly 519 ft tall so you'll spend most of your hour getting to the top (nearest station Blackpool North).
Play: hire a group of players to perform Tom Stoppard's hour- long play Artist Descending a Staircase (with a cast of six men and one woman) in your garden. The script is pounds 5.25 from French's Theatre Bookshop (0171 387 9373). Steinberg and Clarke (0181 877 1102) can provide performers at pounds 70 a person.
And if they're not...
Scholarly: look at one of the Books of Hours. They are lavishly illuminated medieval manuscripts of devotion, originally meant for prayer. They are very fragile and are only displayed as works of art at some larger libraries. Contact the British Museum Library (0171 412 7000) for more details.
Steamy: seduce your partner with the lights off but curtains open. You'll have all the lighted excitement of daytime sex without the inconvenience of having to get up and carry on with the day. If single, invite your object of desire around for a "British Summer Time Dinner" (followed by the above, if you're lucky...)
compiled by Dorothy Koomson