Yes leucojum can flower depending on the variety from January through to May.
E A Bowles in his classic "My Garden in Spring", published in 1914, had this to say about Leucojum:
The Spring Snowflake is so nearly a Snowdrop and flowers with the later ones that I shall praise it here. My favourite form is that known to science as Leucojum vernum, var. Vagneri, but which lies hidden in catalogues and nurseries as carpathicum. Both are larger, more robust forms than ordinary vernum, and strong bulbs give two flowers on each stem, but whereas carpathicum has yellow spots on the tips of the segments, Vagneri has inherited the family emeralds. It is an earlier flowering form than vernum, and a delightful plant to grow in bold clumps on the middle slopes of the flatter portions of the rock garden. Plant it deeply and leave it alone, and learn to recognise the shining narrow leaves of its babes, and to respect them until your colony is too large for your own pleasure, and you can give it away to please others.
L. Hernandezii, also known as L. pulchellum, has won a place in my affections by its useful preference for wet feet. Like the larger and finer, but later L. aestivum, it thrives well on the very edge of water, and looks so much better there than anywhere else, that I advise such a planting. Hernandezii flowers over a long period, throwing up a succession of flower-stems, and it comes in Daffodil days, at a time when other white water-side flowers are asleep.
Note what he says about his "Hernandezii " flowering longer and earlier. A correspondent to the Pacific Bulb Society email list living in Kansas City, Missouri reports that L. aestivum blooms prior to L. vernum there. Leucojum is from Greek - literally "white violet". This seems to be the accepted modern spelling but many would say the older one - Leucoium was more faithful to the Greek derivation.

Thanks for that I believe this is a Vernon the pic I chose is just a library pic and not the one I'm particularly talking about which I have no pic of. Just to say it was flowering at around 12 inches in a friends garden the other snowflakes I've seen seem to flower later and they are a much more robust 3ft. But thanks for settling a argument with my friend who claims it's a "large snowdrop"

Yes! I saw some in a local rock garden a fortnight ago. I was really surprised to see them in flower so early!

Interesting about the two ways of spelling Leucojum. Its probably because some older alphabets, Greek in this case, didn't have a letter j. Latin and Hebrew didn't have it either.
In fact the letter didn't exist before the 1600s. So either spelling is acceptable.