The laycan is the period during which the barge owner must indicate that the barge is at the barge terminal and ready for loading.
The word 'laycan' is a combination of 'laydays' and 'cancelling', which are the first and last days of the period. The charterer does not have to accept the barge until the laydays date, even if the barge is ready earlier. If the barge is not ready by the cancelling date, the charterer may reject the barge.
Read more about Despatches by Barge (Service Trips) or see how to Specify a Laycan for a Service Trip or Accept or Reject a Service Trip Laycan.