Short answer: Submission preparation time depends on the condition of the manuscript, the journal’s requirements, the number of files, formatting complexity, and whether the author has all required declarations and supporting documents ready.
Straightforward formatting may be quick, while a manuscript requiring language editing, figure corrections, reference work, supplementary files, or a cover letter takes longer.
Journal submission systems may also require author information, funding details, conflicts of interest, ethics statements, suggested reviewers, or data-availability information. These must come from the authors.
Plan time for a final author check before submission rather than treating the provider’s delivery time as the journal’s submission deadline.