engineering district；maintenance of way section；track division；track district；track maintenance division

First frost date and late frost date

first frost date and latest frost date

Girst frost date and late frost date

onset date and end date

onset date and ending date

order due date prior to current date

order due date prior to planning start date

order starting date adjusted to calendar date

2-level maintenance

3 level maintenance tset

accelerate maintenance

accident maintenance

accidental maintenance

Active maintenance

active maintenance downtime

active maintenance time

active preventive maintenance time

Adaptive Maintenance