This paper examines the impact of secularization on marriages during Advent and Lent in two Flemish provinces (West-Flanders and Flemish-Brabant) and Brussels-capital. The evolution of the level of church control of the marriage ban (a measure of the process of secularization) between the early 19th and the early 20th centuries is measured through a daily Lent and Advent (DLA) marriage-index. A low index points to a higher level of church control and a lower level of secularization, while a high index points to a lower level of church control and a higher level of secularization. Sub-samples of civil marriage registers are analysed. Results show that the DLA-indexes are low in the early 19th century but increase slowly and consistently throughout the rest of the 19th century, albeit with geographical variations. Spatial differences can be explained by different socio-economic and cultural characteristics of the regions and the populations. Some common underlying factors across locations are identified: change is driven mainly by less religious municipalities and non-native, skilled and, to some extent, elite brides, but less by the self-employed farmers and fishermen, regardless of gender. We also find evidences of low likelihoods of Lent marriages for elite grooms, but high likelihoods of Advent and Lent marriages for skilled brides, and also to some extent of high likelihoods of Advent marriages for elite brides.