The Indus Dictionary Project
This is the noun time with the addition of a ruler. The ruler has three spaces, which translates as three hours.
You should note that the ruler has a straight edge which indicates a precise measurement. This symbol refers to exactly three hours.
Mohenjo-daro: Tablet: M-470 A: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 113: Collections in India: Suomalainen Tiedeakatemia.
Tablet M-470 was probably a token for porterage. The tablet was found in a house in section G of the DK area of Mohenjo-daro. It is therefore, interesting to see Jonathan Kenoyer's photograph of a lane in that neighbourhood, which would have been inaccessible to oxcarts¹.
Indus Script Sign Number 2039: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.
1. Narrow Lane, DK-G Area: Jonathan Mark Kenoyer: Harappa.com: https://www.harappa.com/indus6/mohenjodarostreet63.html: Accessed: 29 April 2020.