This article examines the complex law relating to the date at which interests in land are to be taken as fixed for compensation purposes. Begins with a brief discussion of the decision Birmingham Corporation v West Midland Baptist Trust Association (1969) 20 P&CR 1052 which has exercised an important influence on later decisions relating to the appropriate date for the fixing of interests in land . Goes on to examine the authority for the proposition that interests in land are fixed as at the date an acquiring authority serves notice to treat in respect of land, referred to as the "traditional" approach; discusses a number of decisions pre the West Midland Baptist Case which appeared to depart from the "traditional" approach and finally considers cases decided since the West Midland Baptist Case which tend to support the view that interests as well as values are now to be taken as at what has come to be known as the valuation date .