WSA Posted August 20, 2018 Author Share Posted August 20, 2018 So yeah...couldn't help but notice the time stamp on the FLIR video (12:58 AM), which is reported to have been an hour earlier than actual. What is up with that? :-) 1 Link to comment Share on other sites More sharing options...
joebeelart Posted August 21, 2018 Share Posted August 21, 2018 (edited) Good observation, really. Most of us don't really pay much attention to the date / hour setting on our instruments. Let's face reality; a good recording is at most, rare, so super attention to detail isn't a primary priority after 15 nights afield in group camps and one as an investigative group, so far this year with 7 more scheduled in group camps of 8-16 people. I just noticed I hadn't set one of my trail cams to daylight time { PST vs. PDT }. If it was talking clicks, it would be off. So, I checked my prime digital camera, and guess what? I hadn't reset it to daylight time either. So, all my clcks since spring are off an hour. What you mentioned is an excellent point, possibly easily explained, especially by those who set out camera for many months, and even a year. Joe here Edited August 21, 2018 by joebeelart Link to comment Share on other sites More sharing options...
hiflier Posted August 22, 2018 Share Posted August 22, 2018 And also folks like me who are on the road go through time zones and so even though I may adjust my watch I may, and usually do, forget to reset the trail cam's time. Which reminds me, my planned trip to the PacNW may be cancelled due to the amount of smoke in the region and even a bit further East. I am disappointed but cannot see me, my spouse, and my dog breathing air that at all of our ages would not be good quality. We are mid to late 60's and my dog is 11. It really bums me out to even have to say this but Montana to Tahoe may be all I do this trip. Link to comment Share on other sites More sharing options...
BC witness Posted August 22, 2018 Share Posted August 22, 2018 When had you planned to get out here to the PNW, hiflier? Right now the smoke is terrible over much of BC, including the Fraser Valley/Harrison Lake area, with visibility down to 4 or 5 km most days recently, but a few days of rain could douse most of the fires and clear the air again. PM me when you're headed this way, and I'll keep you updated. Link to comment Share on other sites More sharing options...
gigantor Posted August 23, 2018 Admin Share Posted August 23, 2018 About Daylight Savings Time in sighting reports. When a witness submits a sighting report, one of the questions is: what time did it happen? The witness provides the local time, which includes DST. It is not necessary for us to adjust the time provided by the witness. Link to comment Share on other sites More sharing options...
WSA Posted August 23, 2018 Author Share Posted August 23, 2018 Which raises something I've been thinking about. Assuming BF neither "leaps forward" nor "falls back", any time of encounter given by a witness would have to be adjusted for celestial, non-DLS, time, if it happened during DLST in a state or province that recognizes that, before the data would be truly apples-to-apples, no? Link to comment Share on other sites More sharing options...
gigantor Posted August 23, 2018 Admin Share Posted August 23, 2018 1 hour ago, WSA said: Which raises something I've been thinking about. Assuming BF neither "leaps forward" nor "falls back", any time of encounter given by a witness would have to be adjusted for celestial, non-DLS, time, if it happened during DLST in a state or province that recognizes that, before the data would be truly apples-to-apples, no? No. IMO, the local time is the local time. Every state in the union uses DLST, except for Arizona (which is a big desert) and Hawaii. Link to comment Share on other sites More sharing options...
WSA Posted August 23, 2018 Author Share Posted August 23, 2018 I think you miss my point Gigantor (and leaving aside the fact the database does contain AZ sightings, and many sightings predate the adoption of DST too). If you are wanting to document the chronologic behaviors of a species, a consistent measurement standard needs to be applied. I think we could agree that needs to be local standard celestial time. If some of your sightings are pegged to local standard time, and some of them occur during DST and an allowance is not made to make those consistent, you are not doing a same fruit comparison. You have then a built-in error of +1 hour for some of your measurements. Can that really be disputed by anyone? Link to comment Share on other sites More sharing options...
gigantor Posted August 23, 2018 Admin Share Posted August 23, 2018 ^^^ Now, now Counselor. We all know you have a vested interest in getting the stats to show a 2am increase in events. And technically you are correct, but we're not tracking satellites here... A +-1 hour difference has little impact for our purposes. All we need to show is that the animal is nocturnal and the sightings are not due to regular human activity. 2 Link to comment Share on other sites More sharing options...
Caenus Posted August 23, 2018 Share Posted August 23, 2018 Even if the scale was 4 hours, the data would show similar, I agree with Gigantor. Link to comment Share on other sites More sharing options...
WSA Posted August 23, 2018 Author Share Posted August 23, 2018 Oh no...I'm convinced my impressions on that point were probably skewed. I do think the data is accurate enough to put that idea to rest, and I'm grateful you had the information to share with me. So if all the time stamp was/is intended to do is show nighttime vs. daytime sightings? A +/- error of one hour is all that is needed to make those results invalid. It also is not calibrated to show evidence of crepuscular behavior either....just sayin'. (Disclaimer: Nothing in this post should be deemed to be an offer by the poster to re-calibrate all the sighting reports in the database to local celestial time. ) Link to comment Share on other sites More sharing options...
gigantor Posted August 23, 2018 Admin Share Posted August 23, 2018 (edited) 1 hour ago, WSA said: A +/- error of one hour is all that is needed to make those results invalid. Not so. Please look at the chart again. Edited August 23, 2018 by gigantor p.s. the daylight savings time could easily be adjusted programmatically, but it is not necessary. 1 Link to comment Share on other sites More sharing options...
WSA Posted August 23, 2018 Author Share Posted August 23, 2018 Sure. So take the 7 PM sightings for instance...which appears to me to measure all sightings between 7:00 and 7:59 PM, right? Those could all be 8:00 to 8:59 PM DST sightings, and there is no way to say for sure, right? If the sightings occurred during months where sunset is at or around, say, 7:20 PM celestial time, a DST sighting of 8:20 would indicate it was fully dark when in actuality it was still in a period of statutory twilight. With this error built into the data I'm not sure the time measurement really gets you anything very useful at all unless the sighting took place in the middle of the day, or the middle of the night. Not sure that even has any real significance. I think it is axiomatic (at the data shows this) that BF encounters occur at all hours of they day, weighted towards nighttime activity. From that point of view the actual hour doesn't tell you much of interest, but my original point is it could be recalibrated to tell much more. If I'm missing something, or misinterpreting something, please flag it for me. While I'm on the subject, here is a handy calculator I use on occasion, which you've probably seen. It does adjust for Standard (celestial) and Daylight times, according to the date you enter and the location, and delineates periods of civil twilight. http://aa.usno.navy.mil/data/docs/RS_OneDay.php Link to comment Share on other sites More sharing options...
gigantor Posted August 23, 2018 Admin Share Posted August 23, 2018 43 minutes ago, WSA said: If I'm missing something, or misinterpreting something, please flag it for me. I did. The +/- 1 hour adjustment does not matter in order to show that the animal is nocturnal. Further, it does not matter in order to show that there are more sightings between 9pm and 4am when people are normally asleep; thus, eliminating the possibility that the pattern is due to normal human activity. In other words, there are more sightings at night when camping, driving and fishing because of the animal's behavior. Adjusting for DST is no biggie programmatically, it's just not necessary. 1 Link to comment Share on other sites More sharing options...
Redbone Posted August 24, 2018 Share Posted August 24, 2018 (edited) 1 hour ago, WSA said: So take the 7 PM sightings for instance...which appears to me to measure all sightings between 7:00 and 7:59 PM, right? Those could all be 8:00 to 8:59 PM DST sightings, and there is no way to say for sure, right? If the sightings occurred during months where sunset is at or around, say, 7:20 PM celestial time, a DST sighting of 8:20 would indicate it was fully dark when in actuality it was still in a period of statutory twilight. With this error built into the data I'm not sure the time measurement really gets you anything very useful at all unless the sighting took place in the middle of the day, or the middle of the night. Not sure that even has any real significance. I think it is axiomatic (at the data shows this) that BF encounters occur at all hours of they day, weighted towards nighttime activity. From that point of view the actual hour doesn't tell you much of interest, but my original point is it could be recalibrated to tell much more. If I'm missing something, or misinterpreting something, please flag it for me. I was not planning to jump in here but watching this conversation unfold has urged me on. It's senseless to worry about DST with this data and probably futile to attempt to measure differences hour by hour. The problem here is the accuracy of the thousands of reports that went into this. BFRO doesn't demand accurate time of day information. Most of the time we'll get 'afternoon' or even 'night time" and we're left to guess what that means when entering the data. As much as possible, we use an educated guess to portray what we have as accurately as possible. Still, you get what you get. I'd never count on these reports to give an extremely accurate view of 7:20 vs 8:20 pm. Daylight savings time introduces no more error than what is already there. Many report don't even really specify a month. We get "summer" or "fall" at sundown and now we have to guess twice. If you need more accurate information to pursue a hypothesis, you will need a way to weed out all that contain guess work and only view reports that give exact time. Good luck with that... Don't ask me to go through 5000 reports (again) trying to flag those down for you. Edited August 24, 2018 by Redbone 1 Link to comment Share on other sites More sharing options...
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