they will suffer from cool temps and I see you are in Wales. Personally I wouldn't start them off until March late feb at the earliest. On your windowsill they will be warm enough but they will get leggy before you can plant them in bigger pots.
are you growing them outside or in a greenhouse/lean too?
My daughter grew some outside in Bridgend but they didn't do much until may/june when it was warm enough.

I usually begin mine late February. They will take a whole week to germinate. If you can't give them 5-6 hours of direct sun, grow lights will certainly help and prevent them from getting leggy, also rotating the plants. They will be ready to plant out by late April.

I don't plant mine out in the greenhouse until the end of May, I will start my seeds mid March on the bathroom windowsill.

I start mine the second half of March. They go in the airing cupboard first for two or three days - as soon as the first sign of germination occurs (you need to check daily), they come out on to the kitchen windowsill

Thank you all so much. I will heed your advice, I was asking early as i always seem to miss the boat.Happy gardening all of you.

Even if you miss the boat there are plants available usually until June, of course not a much fun or choice as there is from seed

I'm Hampshire and sow much same times as above. I've found later ones often catch up with the early birds due to longer daylight hours & warmth

Thank you Grandad from grandma

I use home-made light reflectors to reduce legginess in seedlings ..... seedling pots sit in half a lidless shoe-box lined with foil on my windowsills. They grow sturdier, similar to a heat-mat in the greenhouse as they get some heat from the radiators below the windowsills. ( the shoe-box lid reinforces the base of the reflector-box, so the whole set-up is more rigid). Way back in April 2009 I wrote a blog about these 'Windowsill Light Reflectors'

Thank you Xela, I shall certainly do that. A laugh for you all. I always buy blue hyacinth bulbs but always get red pink or white flowers instead.Is there a certain way to get blue ones?