E. Part-Time Practical Experience. In evaluating documented part-time practical aviation mechanic experience, an equivalent of 18 months for each rating individually (or 30 months of concurrent rating experience), based on a standard 40-hour work-week, is acceptable. The months need not be consecutive. A standard work-week has 8 hours per day for 5 days per week, thus totaling 40 hours per week and approximately 160 hours per month.