How to create Gantt Chart in spreadsheet

1 make task list

WBS	TASK TITLE	SCHEDULED START	SCHEDULED FINISH	DURATION IN DAYS	Start on day
1	prepare knowledge	10/22/2020	11/14/2020	24	0
1.1	Familiarize google Colab	10/22/2020	10/23/2020	2	0
1.2	Do homeworks associated with this research of cs231n	10/24/2020	11/6/2020	14	2
1.3	Study pandas tutorial	11/7/2020	11/13/2020	7	16
1.4	preliminary study the basics of MySQL	11/14/2020	11/14/2020	1	23
2	build AiCropper	11/15/2020	12/21/2020	37	24
2.1	write summary of document detection paper	11/15/2020	11/15/2020	1	24
2.2	write a proposal for AiCropper	11/16/2020	11/18/2020	3	25
2.3	collecting training images of documents	11/19/2020	11/21/2020	3	28
2.4	design annotation tool algorithm for labeling document	11/22/2020	11/24/2020	3	31
2.5	augmentation data	11/25/2020	11/27/2020	3	34
2.6	design Algorithm	11/28/2020	11/30/2020	3	37
2.7	design AiCropper Model:	12/1/2020	12/21/2020	21	40
3	build transaction element finder	12/22/2020	2/15/2021	56	61
3.1	build transaction element cropper	12/22/2020	12/28/2020	7	61
3.2	write summary for three paper about siamese NN	12/29/2020	1/4/2021	7	68
3.3	Chose one to implementation	1/5/2021	1/25/2021	21	75
3.4	Modify to find transaction elements	1/26/2021	2/15/2021	21	96
4	build AiTag	2/16/2021	4/5/2021	49	117
4.1	Write summary about Yolo series	2/16/2021	2/22/2021	7	117
4.2	Choose one of them to implement	2/23/2021	3/15/2021	21	124
4.3	Find possibility to modify for this research	3/16/2021	4/5/2021	21	145
5	prototype implementation	4/6/2021	7/8/2021	94	166
5.1	Google colab prototype	4/6/2021	5/22/2021	47	166
5.2	Desktop prototype	5/23/2021	7/8/2021	47	213
6	build Application by using iteration development model	7/9/2021	1/5/2022	181	260
	End			0	441
Note: This is a rough schedule, which will be changed if necessary because all data are estimated based on the plan of a Master Thesis

2 main task row

1. for each cell create formula = if(column()-column($startcell)>=start on day and < start on day of next main task, 1,)
2. select conditional formatting , non empty, color
3. select the same foreground color   as color in step 2

3 sub task

    do the same as main task row

example