Might be worth getting out and about this weekend. Here are a sample of arrival dates in Calderdale for migrants over recent years:
Osprey - 28 March ('12)
Little ringed plover - 22 March ('00)
Sand martin - 16 March ('08)
Wheatear - 12 March ('07)
Ring ouzel - 17 March ('02)
Chiffchaff - 2 March ('09)
And with the mild weather of late and forecast for the next few days, something could easily turn up around the weekend?