Lead time in filing H1-b Petition

HI experts,

I got some leads for doing fresh filing for H1-B Visa ( Fy 2017), however they asked me to reach in the beginning of march. My apprehension is that, will it be too late, or Just in time.

Request to provide typical lead time required to be ready for doing filing in the first week of April

20 days is typical lead time. beginning of march is fine but make sure you keep the relationship warm from mid-jan onwards and use this time to do plenty of research on these companies (some of them can be shady ones) and explore multiple options