Dana Whitlow said: > I guess my question is, then, is it sufficient to label the final output > data with the accurate time of the first sample? Or, (heaven forbid) > should I be thinking in terms of time stamping each output sample? There are two types of time stamps: absolute/UTC and relative to some local time like the start of a run or when a system got reset/booted. In your case, you don't need to time stamp individual samples since you can just count samples from the start of the run. If you were discarding uninteresting data, then you would need to time-stamp each batch of what you saved. If you want to compare your data with data from something else, then you need both setups to add an absolute/UTC time stamp. If you are just trying to keep your notebook clean, (was this data from Friday or Saturday?) then you can include a not-great time stamp in the file name. It's not uncommon to include a PPS signal on another channel to let you align your relative time stamps with UTC. That assumes you can get the which second from your system clock. -- These are my opinions. I hate spam.