The unit of time I've been asked to enquire about is kalā . See the reference given by Bill Mak, Hayashi, Takao. 2017. “The Units of Time in Ancient and Medieval India.” History of Science in South Asia 5 (1): 1–116. doi:10.18732/h2ht0h.  See page 4 chart of units of time for abhidānacintāmaṇī and page 5 chart for arthaśāstra.

 

The context is the list of 108 names of Sūrya from mahābharata (3.3.19 thru 3.3. 3,3,28 (pdf of relevant page from critical edition attached) names 51 thru 56 being different units of time. Name 51 in verse 3.3.22 is kalā.