求翻译：承包商应在开工日期后28天内，向雇主提交一份进度计划。当原定进度计划与实际进度或承包商的义务不符时，承包商还应提交一份修订的进度计划。是什么意思？

The Contractor shall start within 28 days after the date, submit a schedule to the employer. When the original schedule and actual progress or inconsistent with the obligations of the contractor, the contractor shall submit a revised schedule.

The contractor shall be commenced within 28 days after the date the employer plans to submit a progress. When the scheduled progress plan and actual progress or contractors when inconsistent with the obligation, the contractor should also submit a revised schedule for the projects.

The contractor should in the operation date latter in 28 days, submit a progress plan to the employer.When original progress plan and actual progress or contractor's voluntary not symbol, the contractor also should submit a revision the progress plan.

The contractor shall within 28 days after the start date to the employer to submit a schedule. When the original schedule and actual progress or when the contractor's obligations do not match, the contractor should also submit a revised schedule.

The contractor shall within 28 days after the start date to the employer to submit a schedule. When the original schedule and actual progress or when the contractor's obligations do not match, the contractor should also submit a revised schedule.