"Within 15 minutes" means "at some time between now and 15 minutes from now."
Otu ahịrịokwu ọkọlọtọ n'etiti ndị na -ahụ maka mọzụlụ bụ na ị ga -eji "nkeji iri na ise aga, nkeji iri na ise - wee megharịa nke a ugboro 15-15."