WEBVTT 1 00:00:00.090 --> 00:00:00.990 In this lesson, 2 00:00:00.990 --> 00:00:04.290 we're going to talk about inaccurate system date and time. 3 00:00:04.290 --> 00:00:07.080 Now, when it comes to inaccurate system date and time, 4 00:00:07.080 --> 00:00:09.930 almost exclusively from a hardware perspective 5 00:00:09.930 --> 00:00:11.100 this is going to be caused 6 00:00:11.100 --> 00:00:13.830 by a battery failing on your motherboard. 7 00:00:13.830 --> 00:00:16.260 Now, every motherboard has a small battery 8 00:00:16.260 --> 00:00:20.460 that helps to keep its RTC or real time clock in sync. 9 00:00:20.460 --> 00:00:22.680 This is because when you shut down your computer 10 00:00:22.680 --> 00:00:24.150 you're removing power to it 11 00:00:24.150 --> 00:00:26.340 and this real time clock needs to have power 12 00:00:26.340 --> 00:00:28.290 to remember what the date and time was 13 00:00:28.290 --> 00:00:30.570 that you set on that particular system. 14 00:00:30.570 --> 00:00:32.160 In modern computer systems, 15 00:00:32.160 --> 00:00:35.370 these are most commonly going to be a lithium coin cell battery 16 00:00:35.370 --> 00:00:39.390 that is going to take the form factor of a CR2032. 17 00:00:39.390 --> 00:00:43.050 Now, the CR 2032 looks like a watch battery, essentially, 18 00:00:43.050 --> 00:00:46.470 and they usually last somewhere between three to five years. 19 00:00:46.470 --> 00:00:48.750 And so if you're somebody who keeps a computer longer 20 00:00:48.750 --> 00:00:51.690 than about three to five years, you may start to have issues 21 00:00:51.690 --> 00:00:53.400 with the date and time of your system 22 00:00:53.400 --> 00:00:54.660 where when you shut down the computer 23 00:00:54.660 --> 00:00:55.830 and you bring it back online, 24 00:00:55.830 --> 00:00:57.450 it forgets what the date is 25 00:00:57.450 --> 00:01:01.170 or the time starts slipping either forward or backwards. 26 00:01:01.170 --> 00:01:02.790 Now, luckily for us these days, 27 00:01:02.790 --> 00:01:04.620 most of our modern operating systems 28 00:01:04.620 --> 00:01:07.650 do set their date and time automatically over the internet 29 00:01:07.650 --> 00:01:10.800 by talking to a centralized network time protocol server. 30 00:01:10.800 --> 00:01:12.720 But if you're not connected to the internet 31 00:01:12.720 --> 00:01:15.420 you are going to notice this date/time creep that occurs 32 00:01:15.420 --> 00:01:16.890 and generally this is going to be 33 00:01:16.890 --> 00:01:20.040 because the battery has died on your motherboard. 34 00:01:20.040 --> 00:01:22.800 So why is time so important to us 35 00:01:22.800 --> 00:01:25.560 on a computer that we have to have its own battery 36 00:01:25.560 --> 00:01:27.450 on the motherboard to protect it? 37 00:01:27.450 --> 00:01:29.370 Well, this all comes down to the fact 38 00:01:29.370 --> 00:01:32.100 that time keeping needs to be done accurately 39 00:01:32.100 --> 00:01:34.530 for a wide variety of things on our systems, 40 00:01:34.530 --> 00:01:37.410 including the creation date of files and directories, 41 00:01:37.410 --> 00:01:39.420 being able to communicate to other computers 42 00:01:39.420 --> 00:01:41.400 over the network or over the internet 43 00:01:41.400 --> 00:01:43.530 because a lot of our authentication relies 44 00:01:43.530 --> 00:01:45.390 on a time based signature protocol, 45 00:01:45.390 --> 00:01:48.000 and so if we're not all using the same type of time, 46 00:01:48.000 --> 00:01:49.320 this can actually cause issues 47 00:01:49.320 --> 00:01:51.280 and you won't be able to connect 48 00:01:51.280 --> 00:01:52.770 to servers and other things like this. 49 00:01:52.770 --> 00:01:54.990 And so it's really important that you make sure the time 50 00:01:54.990 --> 00:01:57.360 is accurate on your system within a couple of minutes, 51 00:01:57.360 --> 00:01:59.550 and that the system can remember that time 52 00:01:59.550 --> 00:02:01.560 whenever you remove power from it. 53 00:02:01.560 --> 00:02:03.990 Now, I mentioned that most motherboards are going to be 54 00:02:03.990 --> 00:02:07.080 using a small circular coin size battery 55 00:02:07.080 --> 00:02:09.540 that is called a CR2032. 56 00:02:09.540 --> 00:02:12.210 This does depend on your make and model of motherboard 57 00:02:12.210 --> 00:02:13.980 and so check your motherboards documentation 58 00:02:13.980 --> 00:02:15.540 to ensure you're getting the right battery 59 00:02:15.540 --> 00:02:16.830 for your motherboard. 60 00:02:16.830 --> 00:02:18.210 On some older systems, 61 00:02:18.210 --> 00:02:20.400 they didn't use these coin style batteries, 62 00:02:20.400 --> 00:02:22.140 and instead they used the battery 63 00:02:22.140 --> 00:02:24.150 that actually looked like a computer chip 64 00:02:24.150 --> 00:02:26.010 that would actually be plugged into the motherboard. 65 00:02:26.010 --> 00:02:27.390 And so these were very specific, 66 00:02:27.390 --> 00:02:29.880 and made by each individual motherboard manufacturer 67 00:02:29.880 --> 00:02:31.740 and you'd have to buy it from them. 68 00:02:31.740 --> 00:02:33.120 Thankfully, over time, 69 00:02:33.120 --> 00:02:34.800 we kind of got to this standard system 70 00:02:34.800 --> 00:02:36.636 of these coin type batteries of the CR2032s 71 00:02:36.636 --> 00:02:40.140 that are used across most motherboards. 72 00:02:40.140 --> 00:02:42.660 Now, another major change we've seen over time is 73 00:02:42.660 --> 00:02:46.500 that we've moved from what's called a CMOS into NVRAM 74 00:02:46.500 --> 00:02:49.410 for being able to store the bios and UEFI data. 75 00:02:49.410 --> 00:02:50.370 Now, in the old days, 76 00:02:50.370 --> 00:02:52.560 we had this thing called CMOS, which stands for 77 00:02:52.560 --> 00:02:55.440 the complimentary metal-oxide-semiconductor, 78 00:02:55.440 --> 00:02:57.420 and this described the manufacturing process 79 00:02:57.420 --> 00:02:59.730 that was used to create this type of of memory. 80 00:02:59.730 --> 00:03:02.190 This memory, though had to constantly be refreshed 81 00:03:02.190 --> 00:03:04.350 inside of it, otherwise we would lose the settings. 82 00:03:04.350 --> 00:03:06.990 And to do that when the power was removed from the system, 83 00:03:06.990 --> 00:03:08.820 it would rely on this battery 84 00:03:08.820 --> 00:03:10.740 in the motherboard to be able to keep power 85 00:03:10.740 --> 00:03:13.950 to that CMOS and ensure that those settings weren't lost. 86 00:03:13.950 --> 00:03:16.650 Now, over time, this CMOs was actually replaced 87 00:03:16.650 --> 00:03:18.510 with something called NVRAM, 88 00:03:18.510 --> 00:03:20.610 which stands for non-volatile ram. 89 00:03:20.610 --> 00:03:23.280 Now, on these modern motherboards that use NVRAM 90 00:03:23.280 --> 00:03:24.930 or non-volatile RAM, 91 00:03:24.930 --> 00:03:27.120 these things can actually store the data 92 00:03:27.120 --> 00:03:29.430 without having to be constantly refreshed. 93 00:03:29.430 --> 00:03:30.690 You can remove power from it 94 00:03:30.690 --> 00:03:33.210 and it will still remember everything you stored there. 95 00:03:33.210 --> 00:03:35.700 Essentially, think about it like your USB flash drives 96 00:03:35.700 --> 00:03:37.530 or your solid state devices. 97 00:03:37.530 --> 00:03:39.780 These things are also made out of NVRAM, 98 00:03:39.780 --> 00:03:41.520 and so when you remove power from them, 99 00:03:41.520 --> 00:03:43.290 the data still remains. 100 00:03:43.290 --> 00:03:45.720 Now, in the older CMOS, that was not the case 101 00:03:45.720 --> 00:03:48.030 and so these batteries were vitally important 102 00:03:48.030 --> 00:03:50.010 because if that battery died on you, 103 00:03:50.010 --> 00:03:51.960 you would lose not just your date and time, 104 00:03:51.960 --> 00:03:53.790 but also all of your settings that you create 105 00:03:53.790 --> 00:03:56.580 inside your bios, including your bios passwords 106 00:03:56.580 --> 00:03:59.280 your storage device settings, and things like that. 107 00:03:59.280 --> 00:04:00.113 So back then, 108 00:04:00.113 --> 00:04:02.550 it was really important to make sure you had a good battery 109 00:04:02.550 --> 00:04:05.100 on your motherboard to hold not just the date and time, 110 00:04:05.100 --> 00:04:06.660 but also all of these settings 111 00:04:06.660 --> 00:04:10.500 inside the bio or UEFI inside of your CMOS. 112 00:04:10.500 --> 00:04:13.440 All that being said, for the exam, I want you to remember 113 00:04:13.440 --> 00:04:15.450 that there is a battery on your motherboard 114 00:04:15.450 --> 00:04:18.120 and anytime you start having date or time issues, 115 00:04:18.120 --> 00:04:19.440 it could actually be tied to the fact 116 00:04:19.440 --> 00:04:21.330 that that battery is now out of power 117 00:04:21.330 --> 00:04:23.580 and it has died and needs to be replaced. 118 00:04:23.580 --> 00:04:25.800 Also, when you talk about this battery 119 00:04:25.800 --> 00:04:28.560 a lot of people will call this a CMOS battery. 120 00:04:28.560 --> 00:04:30.630 Technically, that's not accurate anymore 121 00:04:30.630 --> 00:04:32.370 because we don't really use CMOS. 122 00:04:32.370 --> 00:04:33.810 We use NVRAM. 123 00:04:33.810 --> 00:04:35.220 But on the exam, 124 00:04:35.220 --> 00:04:37.710 if you see a question that mentions the CMOs battery 125 00:04:37.710 --> 00:04:39.750 or the real time clock battery, 126 00:04:39.750 --> 00:04:41.550 we're really talking about the same thing here 127 00:04:41.550 --> 00:04:43.950 when we're talking about that CR2032 128 00:04:43.950 --> 00:04:46.850 and it's the current standard on most modern motherboards.