I have attached the summer schedule for the Orange Line. This is the scheduled arrival and departure times, providing that there are no service interruptions. I hope this can help you during your commute. I have suggested that this schedule be posted on the website and at stations. I hope that your frustrations and e-mail will generate a positive change at the MBTA.
wow, an actual, useful response! until they post this useful info online, i've put them up:
summer orange line northbound
summer orange line southbound