Make a Simple Project Timeline in Excel

A simple project timeline in Excel needs two things: dates that respect weekends and holidays, and a visual bar for each task. WORKDAY handles the dates, so the plan updates itself when one task moves, and conditional formatting draws Gantt-style bars without a chart. This guide builds a five-task plan for a small website project. It suits anyone who plans work in Excel, from coordinators to project managers.

What the project timeline will look like#

The plan has a task table on the left and a grid of weeks on the right.

You type only the first start date and the Days column. Every other date is a formula. Holidays go in a separate list, P2:P6. Here there is one: Friday 4/18/2025.

Step 1: List the tasks and their working days#

Write each task on its own row and estimate its length in working days, Monday to Friday. Working days are easier to estimate than calendar days, because nobody plans a task over a weekend.

Type the project start in B2: 3/3/2025, a Monday. Format the date columns with Ctrl+Shift+# (Mac: Control+Shift+#) if they show numbers. Dates in Excel are numbers underneath, which is what lets the formulas below count days.

Step 2: Work out end dates with WORKDAY#

WORKDAY returns the date a given number of working days after a start date, skipping weekends and any holidays you list:

=WORKDAY(start_date, days, [holidays])

WORKDAY doesn't count the start date itself. A 3-day task that starts on Monday ends on Wednesday, which is 2 working days after the start. So subtract 1 from the days. In D2:

=WORKDAY(B2,C2-1,$P$2:$P$6)

Kick-off starts 3/3/2025 and ends 3/5/2025. The holiday range is locked with $ so it stays the same when you fill down. The exercise on this page uses the same formula on a task that runs over a holiday.

Step 3: Chain each task to the one before#

Most tasks start when the previous one ends. Instead of typing start dates, start each task one working day after the last one finishes. In B3:

=WORKDAY(D2,1,$P$2:$P$6)

Fill B3 down to B6, and D2 down to D6. Now look at Launch: Testing ends on Thursday 4/17, Friday 4/18 is a holiday, so Launch starts on Monday 4/21.

This is where formulas pay off. Change Design from 8 days to 10, and Build, Testing and Launch all move two working days later by themselves. Our guide to counting working days with NETWORKDAYS and WORKDAY covers both functions in more depth.

Step 4: Check the plan with NETWORKDAYS#

NETWORKDAYS counts the working days between two dates, including both the start and the end. Use it to check the plan. In E2:

=NETWORKDAYS(B2,D2,$P$2:$P$6)

Each row should match its Days column. For the whole project, =NETWORKDAYS(B2,D6,$P$2:$P$6) gives 35 working days, which is 3 + 8 + 15 + 8 + 1. If the number is bigger than the sum of the tasks, there is a gap between two tasks; if it is smaller, two tasks overlap.

For a countdown, =NETWORKDAYS(TODAY(),D6,$P$2:$P$6) shows the working days left until launch. TODAY changes every day, so the number updates whenever the file opens.

Step 5: Add a week grid for the Gantt bars#

A Gantt chart shows each task as a bar across time. In Excel, the simplest version is a row of dates across the top with colored cells. Start in G1 with the Monday of the first week:

=B2

In H1, type =G1+7 and fill right to N1. That gives eight weeks, from 3/3 to 4/21. Format the headers as m/d (Ctrl+1 or ⌘1 > Custom) to keep them narrow, and make the columns about as wide as the dates.

Step 6: Draw the bars with conditional formatting#

A formula rule colors a cell when the formula is TRUE. Each grid cell should turn on when its week overlaps the task's dates.

1. Select the grid, G2:N6.
2. Choose Home > Conditional Formatting > New Rule > Use a formula to determine which cells to format.
3. Enter this formula, written for the top-left cell, G2:

=AND($B2<=G$1+4,$D2>=G$1)

4. Click Format, choose a fill color and click OK.

The week in G1 runs from Monday (G1) to Friday (G1+4). The task overlaps that week if it starts on or before Friday and ends on or after Monday. The $ signs matter: $B2 and $D2 keep the columns fixed so every cell reads its own task's dates, and G$1 keeps the row fixed so every cell reads its own week.

For a daily grid, put one working day per column (=WORKDAY(G1,1,$P$2:$P$6) across row 1) and use the simpler rule =AND(G$1>=$B2,G$1<=$D2). The conditional formatting guide explains formula rules step by step.

Make the timeline easy to share#

• Add a Status column with a drop-down (Not started, In progress, Done), and a second rule such as =$F2="Done" that colors finished rows grey.
• Mark milestones, like Launch, with a different color using a rule that checks the task name or a Milestone column.
• Freeze panes at G2 (View > Freeze Panes) so task names and weeks stay visible as you scroll.
• Use WORKDAY.INTL if your team's weekend isn't Saturday and Sunday.

Date math like this is a common task in Excel tests; it appears in our practice tasks to do before an Excel test. For another project, try an expense tracker or a sales commission calculator.

Practise it#

Do the exercise on this page to find a task's end date across a holiday. Then practise NETWORKDAYS and WORKDAY with holidays and backwards scheduling, and practise conditional formatting, including formula rules that color whole rows.