The difference between our premortal life and earth life is we were spirits only with no body of flesh and bones. It was a most beautiful place were we didn't need to learn faith or how to control our bodies for we didn't have one yet. Thou we went through a lot of learning to prepair us for earth life.Which is a very important phase,probably the most important one. How long we don't know it could of been eons.I don't beleive the time frame matters. How great our Heavenly Father is for He is so organized, for His wisdom, His knowledge,for His love for all of His children for He knew all his children would need to learn and grown and progress and He wants the best for us!!!!!