Cannot figure out syntax to display a time of day in a formula text field

I thought of that but unfortunately, I use a non-native app that updates and creates records in other locations of my system and I already have everything written using a separate date field. To change it at this point has ripple effects that would take longer than I have to spend on the project to correct. I know that my syntax is off and that ToFormattedText is not correct but is there any syntax that will convert a time of day field to display in a formula text field as part of a formula? Thanks for your suggestion!