Critics claim that the on-time performance (OTP) calculated by the LIRR is manipulated to be artificially high. Because the LIRR does not release any raw timing data nor does it have independent (non-MTA) audits it is impossible to verify this claim, or the accuracy of the current On Time Performance measurement. The percentage measure is used by many other US passenger railroads but the criticism over accuracy is specific to the LIRR. As defined by the LIRR, a train is "on time" if it arrives at a station within 5 minutes and 59 seconds of the scheduled time. The criterion was 4 minutes and 59 seconds until the LIRR changed it because of a bug in their computer systems. Critics believe the OTP measure does not reflect what commuters experience on a daily basis. The LIRR publishes the current OTP in a monthly booklet called TrainTalk. TrainTalk was previously known as "Keeping Track." A more accurate way to measure delays and OTP has been proposed. Called the "Passenger Hours Delayed" index it can measure total person-hours of a specific delay. This would be useful in comparing performance of specific days or incidents, day-to-day (or week-to-week) periods, but has not been adopted.