The entire product feature can be done on a google calendar. This tool can be a competitor for asana.
Edit. - I tried the tool for a trip I am going on. This is good. But I dislike the refresh blocking any action even on resizing the event.
Thanks for the review @judeosby. We're still early in our development process and are releasing new features specifically geared towards collaborative travel planning all the time. Happy to hear any suggestions you may have to help us be better