Select the cell to change.
Right click.
Select Format Cells from the dropdown menu.
In the Category list, select Time, and choose format.
Select cells to merge.
On the Home tab, select the Merge & Center.
Select the merge option from the dropdown menu that best suits your needs.
Select the cells to unmerge.
On the Home tab, select Merge & Center.
Select Unmerge Cells.
Insert a table in your spreadsheet.
Select a cell within your data.
Select Home.
Left-click Format as Table.
Choose a style for your table.
Set your table range within Format as Table.