Highlight days in a Gantt

As moderator of TECHNET forums about Project Server / Online, I often have interesting questions which push me digging concerns I would never have considered.

One recent question I had was as followed. So back to MS Project basics, this is quite simple and immediate to set up but it can bring visibility to stakeholders whom you're sharing the plan with.

"How could we highlight days on an existing task? For example, customer visit on site, strike, MEP, etc... We don't want to create additional tasks or work, neither to create exceptions."

So before going through the steps, here is the final result you can achieve with a 5-minutes configuration.

Starting with the following 10-days new task:

First concept to understand: the bar styles. If you double click on the Gantt chart, you'll open the following configuration box:

You can see that each type of task (normal, manual, critical, milestone, summary, baseline, etc...) has a specific style which can be customized. You might remember that I wrote a post a while ago about customizing bar style based on custom flags. You can also see that each style has a start and a finish. For standard tasks, it is obviously [start] and [finish], whereas for baseline tasks, this is [baseline start] and [baseline finish]. This allows displaying baseline above the task as shown below. 

You understand that mastering bar styles can be quite useful whenever you fall into Gantt customization. So back to our use case, the principle is to use custom start and finish dates. 

1- You can start with the start1/finish1 but you could use additional custom dates if you want to highlight multiple slots.

2- Then customize bar styles with start and finish dates 1 and 2. Note that the new bar styles have to be created BELOW the standard task style so it will be shown on top. Otherwise it would not be visible.

Here is what you get, clear and simple:

3- You might want to add a label as an explanation for highlighting those days. You can use the text 1 and 2 to enter text, and set those custom fields as text displayed on top or below the bar.

Here is the result:

Leonardo da Vinci used to say: "Simplicity is the ultimate sophistication", what do you think?