How long do i have to use a fresh sperm sample before it is non-viable?

See below: Not clear from your question as to what your intended use is. Once ejaculated, sperm can remain viable for a couple of hours depending on the environment, moisture, and temperature of the surface or in a specimen container. Once dried, sperm become non-viable. Within the female reproductive tract (vagina, uterus, tubes) sperm can remain viable 1-5 days.