You must have Admin Level - Webmaster access to add a swimmer's meet time manually.
Click Events & Competition > Meet Results from the left navigation menu.
Click the Results By Meets tab.
Click Add Meet for Meet Results, fill in the fields, and click Save Changes. If you are entering results from many different meets, perhaps create a generic meet called "Top Meet Results" (for many athletes) or "Chris Smith's Top Results" (for one athlete).
Find the meet you created in the list and click its name.
If it's a relay time, click the Relay Events tab; otherwise, stay on the Individual Events tab.
Click the Add Result button in the upper right (or Add Relay Result).
Pick the Member from that dropdown (or the Relay Team) and enter all details for a particular result.
The Member must exist in your roster. If they do not, you must go into Account/Member Admin and add them before you can add their times.
Click Submit, and that time will populate the meet.
Repeat steps 5-8 until all times are entered.