For a tongue-in-cheek approach to Celtic Revival Christian/NeoPagan seasonal observances, do wander over and meet the
Beaker Folk.

Also, here's a wee Imbolc bit unearthed from the Ceilidh House compost pile:

IMBOLCTIDE

When yon Auld Grannie gyres an gimps
an unco dance on cranreuch groond
an gies her sillar curls a crimp,
Ye ken that Imbolc's comin roond.

When sillar hammers, blaw for blaw
fa habber-haird in hinmaist hone
then haud ye fast, for soon the thaw
will prize awa cauld winter's loan

Nae lang she'll lanesame bide, nor sup
Wi'oot the dochter she lo' best;
Nae grannie redds the kailyird up
But for the thocht o some comin guest!

Nae mair the lanesame anvil-drum
Will mairk the pace o Grannie's dance--
The Lass o the Lintin Wind sall come
An lowpin lambies hae their chaunce--

For Grannie Cailleach's time grows short
An wee snaw-drappies rowthie ring
For Brigid comes, blithe hope tae sport
An aifter Brigid comes-- the Spring!