The onus shall be on the teacher coming on staff of the Board to provide within 60 days of commencement of employment satisfactory evidence of qualification and experience. The salary shall be based on such evidence as is submitted within the said 60 days and any salary adjustment thereafter shall be made effective from the first day of the month following which additional evidence is submitted. Satisfactory evidence shall be documentary evidence that increased qualifications have been registered with the Department of Education. Extension of the 60-day period salary adjustment retroactive to the date of commencement of employment may be granted at the discretion of the Board if and when the delay in submitting evidence is due to circumstances beyond the control of the teacher.