New architectures have recently been proposed and deployed to support end-to-end advance reservation of network resources. These architectures rely on the use a centralized scheduler, which may be unpractical in large or administratively heterogeneous networks. In this work, we explore and demonstrate the feasibility of implementing distributed solutions for advance reservation. We introduce a new distributed, distance-vector algorithm, called Distributed Advance Reservation (DAR), that provably returns the earliest time possible for setting up a connection between any two nodes. Our main findings in this context are the following: (i) we prove that widest path routing and path switching (i.e, allowing a connection to switch between different paths) are necessary to guarantee earliest scheduling; (ii) we propose a novel approach for loop-free distributed widest path routing, leveraging the recently proposed DIV framework. Our routing results directly extend to on-demand QoS routing pro...