Details from the Royal Horticultural Society, Vincent Square, London SW1P 2PE (telephone 0171 630 7422).
Marquees house the main exhibitors, as well as specially designed gardens many of which follow a theme.
Monday is royal private viewing day with a gala charity preview in the evening. Tuesday and Wednesday are RHS members' days, and Thursday and Friday are for the public.
British Antique Dealers' Association Fair
Chelsea, London
Details from BADA/Reed Exhibitions Ltd, Oriel House, 26 The Quadrant, Richmond, Surrey TW9 1DL (telephone 0181 948 9802).
Held during the first week of May.
Rugby Cup Final
Twickenham, London
Details from the Rugby Football Union, Twickenham, Middlesex TW1 1DZ (telephone 0181 892 8161).
International Golf Open
St Mellion, Cornwall
Details from Gallaher Limited, Members Hill, Brooklands Road, Weybridge, Surrey KT13 0QU (telephone 01932 859777).
Cavalry Parade
Hyde Park, London
Details from local press.
Combined Cavalry 'Old Comrades' Parade and Memorial Service at the Cavalry Memorial in Hyde Park, held on the first or second Sunday in May.
Football Association Cup Final
Wembley, London
Details from Football Association, 16 Lancaster Gate, London W2 3LW (telephone 0171 262 4542).
Floral Luncheon
Savoy Hotel, London
Details from Forces Help Society and Lord Roberts Workshops, 122 Brompton Road, London SW3 1JE (telephone 0171 589 3243).
In aid of the Forces Help Society and the Lord Roberts Workshops, held on the first Thursday in May.
Royal Society of Portrait Painters Annual Exhibition
Mall Galleries, London
Details from Royal Society of Portrait Painters, 17 Carlton House Terrace, London SW1Y 5BD (telephone 0171-930 6844).
Includes a mixture of pictures by established painters and members of the public.
ISS Spring Fair
Kensington Town Hall, London
Details from ISS UK, Cranmer House, 39 Brixton Road, London SW9 6DD (telephone 0171 735 8941).
Brings together the diplomatic corps of London in aid of the International Social Service of the UK.
Features stalls from over a hundred countries and many of the diplomatic wives based in London become sales assistants for the day. Each stall is piled high with unusual and attractive produce from each country.
Jester Ball
London
Details from the Action on Addiction Office, 68 South Lamberth Road, London SW8 1RL (telephone 0171 793 1011).
In aid of Action on Addition.
Gulls' Egg City Luncheon
London
Details from The CRMF Appeals Office, 11 Elvaston Place, London SW7 5QG (telephone 0171 581 9225).
In aid of the Cancer Relief Macmillan Fund. Gulls' eggs are the focal point of the menu.
Glyndebourne Opera Festival
Lewes, East Sussex
Details from Glyndebourne Festival Opera, Glyndebourne, Lewes, East Sussex BN8 5UU (telephone 01273 812321).
Held between May and August.
May Balls and Commemorative Balls
Oxford and Cambridge
Given at and by individual Oxford and Cambridge colleges. At Oxford the balls are known as Commem Balls instead of May Balls, but are otherwise the same.
Admission is by ticket but invitations are normally circulated to current undergraduates in January and February and any remaining tickets are then allocated to the public.
For further information, contact the individual colleges. Other universities organise similar festivities.
Major-General's Review, Trooping the Colour
Whitehall, London
Details from Senior Public Relations Officer, London District, Chelsea Barracks, London SW1H 8RF (telephone 0171 930 4466 ext 2396/2357).
Held between the end of May and beginning of June.
Hickstead Nations Cup Show Jumping
West Sussex
Details from Booking Office, All England Show Jumping Course, Hickstead, West Sussex RH17 5NU (telephone 01273 834315).
Remember:
The Proms
Book tickets well in advance. Details from Royal Albert Hall, Kensington Gore, London SW7 2AP (telephone 0171-589 8212).
Royal International Agricultural Society Show
Apply for tickets before mid June to take advantage of a 33% discount. Details from Royal Agricultural Society of England, National Agricultural Centre, Stoneleigh, Warwickshire CV8 2LZ (telephone 01203 696969).