Questa - time precision

You may use timescale to do it, https://www.intel.com/content/www/us/en/docs/programmable/683080/23-1/vcs-and-vcs-mx-guidelines.html

Try with this design example

https://community.intel.com/t5/Intel-Quartus-Prime-Software/Simulating-a-FIFO-using-QuestaSim/m-p/1618441#M83701%3Fwapkw=questasim%20timescale

Do you have further queries? If no, we shall close this thread.

As we do not receive any response from you on the previous answer that we have provided. Please login to ‘https://supporttickets.intel.com/s/?language=en_US’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you on your follow-up questions.