Calypso waits patiently on her island, holding much faith that Leo will come back for her. She paces the beach, mumbling under her breath.
"He's coming back. I know it. He's coming."
What Calypso doesn't know, Leo never figured out the astrolobe. Since he broke his oath that he made on the River Styx, he was killed. Sounds harsh, but swearing on the Styx is serious stuff.
Time is different on Ogygia, so Calypso didn't realize she has been pacing that beach for one year. She didn't realize Leo would never return, because of an oath he made to save her.