From Wikipedia you can read:A Gantt chart is a type of bar chart, developed by Henry Gantt, that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project. Some Gantt charts also show the dependency (i.e., precedence network) relationships between activities. Gantt charts can be used to show current schedule status using percent-complete shadings and a vertical "TODAY" line as shown here.
Are you supposed to draw Gantt charts daily, it maybe worth investing in a pre-purchased package otherwise there are possibilities to create your own Gantt charts.
Free Preceden is one variant I have previously written about. Then you get a nice online schedule, or Timeline as they call it, in colour.
Another option, which is currently free, is the variant from Timios. A truly advanced Gantt chart in which also show the dependency. You download their Gantt designs and can therefore work off-line.
Spread sheet programs are otherwise fine to do Gantt charts in. Templates are available such as Gantt Chart Template for Exel from vertex42. Another is done by Raphael Sedin,who created an excellent template for Gantt in Exel. You can find it here.
Of course you could create your own templates. For Open Office Calc, there is a good description together with a template here that also include project management which is available for download. For Exel, I have previously given an example but you can also read more about it at Microsoft.