Under time charterparty the owner let his vessel to the charterer for a period of time, therefore when compared with single voyage or with series of single geographical voyages under the voyage charter contracts, time charter instead of provisions for freight, laytime and demurrage has stipulations for payment of hire, delivery, redelivery and off-hire events.
Per Mackinnon LJ in Sea and Land Securities v Dickinson  2 K.B. 65:
A time charterparty is, in fact, a misleading document, because the real nature of what is undertaken by the shipowner is disguised by the use of language dating from a century or more ago, which was appropriate to a contract of a different character then in use. At that time a time charterparty (now known as a demise charterparty) was an agreement under which possession of the ship was handed by the shipowner to the charterer for the latter to put his servants and crew in her and sail her for his own benefit. A demise charterparty has long been obsolete. The modern form of time charterparty is, in essence, one by which the shipowner agrees with the time charterer that during a certain named period he will render services by his servants and crew to carry the goods which are put on board his ship by the time charterer. But certain phrases which survive in the printed form now used are only pertinent to the older form of demise charterparty. Such phrases, in the charterparty now before the court, are: "the owners agree to let," and "the charterers agree to hire" the steamer. There was no "letting" or "hiring" of this steamer. Then it is in terms provided that at the end of the period the vessel shall be "redelivered" by the time charterers to the shipowners. "Redelivery" is only a pertinent expression if there has been any delivery or handing over of the ship by the shipowner to the charterer. There never had been any such delivery here. The ship at all times was in the possession of the shipowners and they simply undertook to do services with their crew in carrying the goods of the charterers. As I ventured to suggest quite early in the argument, between the old and the modern form of contract there is all the difference between the contract which a man makes when he hires a boat in which to row himself about and the contract he makes with a boatman that he shall take him for a row.
Dictum of Lord Diplock in Scandinavian Trading Tanker Co AB v Flota Petrolera Ecuatoriana (The Scaptrade)  2 All ER 763 at p.766:
A time charter, …, transfers to the charterer no interest in or right to possession of the vessel; it is a contract for services to be rendered to the charterer by the shipowner through the use of the vessel by the shipowner’s own servants, the master and the crew, acting in accordance with such directions as to the cargoes to be loaded and the voyages to be undertaken as by the terms of the charterparty the charterer is entitled to give to them. Being a contract for services it is thus the very prototype of a contract of which before the fusion of law and equity a court would never grant specific performance: Clarke v Price (1819) 2 Wils. 157; Lumley v Wagner (1852) 1 De G.M & G. 604. In the event of failure to render the promised services, the party to whom they were to be rendered would be left to pursue such remedies in damages for breach of contract as he might have at law. But as an unbroken line of uniform authority in this House, from Tankexpress  A.C. 76 to A/S Awilco of Oslo v Fulvia S.p.A. di Navigazione of Cagliari (The Chikuma)  1 W.L.R. 314, has held, if the withdrawal clause so provides, the shipowner is entitled to withdraw the services of the vessel from the charterer if the latter fails to pay an instalment of hire in precise compliance with the provisions of the charter. So the shipowner commits no breach of contract if he does so; and the charterer has no remedy in damages against him.