The default time format in Excel is the hour, minute, and second. Sometimes, time does not come with seconds, to include seconds for a time, please follow steps below (or see here if you add seconds with AM/PM):
Step 1: Select the cells or range with time and right-click;
Step 2: From the list, click "Format Cells";
Step 3: In the "Format Cells" window, click "Time" from the left navigation, then select "13:30:55" from the list to include second;
Step 4: Click "OK" at the bottom.