<p><span>The transition to alternative marine fuels is usually framed through emissions, safety, and compensation after pollution damage. This article treats the same transition as a problem of commercial time. A vessel may lose time before any spill, fire, explosion, contamination, or injury occurs. The source of delay may be a missing bunkering facility, a fuel-specific safety clearance, port refusal, documentary uncertainty, crew or equipment readiness, incompatibility between the vessel and local infrastructure, or regulatory requirements attached to new fuel systems. Traditional demurrage doctrine can price some of that waiting time, but it does not identify the party that should bear a fuel-transition delay unless the charterparty has done the work in advance. Existing IMO liability conventions address damage after defined incidents. They do not settle the earlier question that is more likely to arise in everyday trade: whether the loss of time caused by alternative fuel use counts as laytime, demurrage, off-hire, excepted time, or a separate compensated waiting period. The article argues for a contractual category of alternative fuel delay and for drafting that links the time risk to control over fuel selection, vessel readiness, bunker procurement, port nomination, and safety documentation.</span></p>