If you're looking for a gantt online free of charge you need to think through what are the needs of you and your team. If you need something for agile planning that can be rearranged quickly, you're in a right place.
Planning and tweaking your schedule is the best way to keep your planning realistic. There's always something that comes up and what you have to alter your plans for. So, it's better to stay flexible.
To rearrange Teamweek, the online schedule planner and team calendar, all you need to do is to drag and drop. To create new tasks just click and drag.
Use bulk move to relocate many tasks at the same time.