Regulations, through the use of obligations and permissions, are widely used in modern society to define acceptable behaviours. Thus it is indeed important that these regulations do not conflict with each other and contain contradicting obligations. In the present paper we focus on identifying conflicts between obligations in dynamic settings. We first show the need of an alternative semantics rather than the more classic modelled by standard deontic logic. Second we introduce a new semantics for the obligations capable of representing and reasoning about them in these dynamic settings, and lastly we use it to identify the necessary and sufficient conditions to identify conflicting obligations.