https://devzone.nordicsemi.com/f/nordic-q-a/67813/rtc-drift-when-lf-rc-is-chosen-in-sdk-config-hHello, I can see RTC drift of around 14 seconds in 1 hr when I select the internal RC oscillator in sdk-config of nrf-calender example. Is this much drift expected? In my perception, 14 seconds of drifts in an hour is very high. The Time calculateden-USTelligent Community 13Fri, 30 Oct 2020 10:54:58 GMThttps://devzone.nordicsemi.com/thread/277779?ContentTypeID=1Fri, 30 Oct 2020 10:54:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:100ef8d6-5944-4c57-b975-e55e86296bffVidar Berg<p>Hello,</p> <p>Assume calibration is not enabled in this example? The RC must be calibrated periodically to reach the +/- 500 ppm accuracy (<span><a title="Calibrating the 32.768 kHz RC oscillator" href="https://infocenter.nordicsemi.com/topic/ps_nrf52840/clock.html?cp=4_0_0_4_3_1_1#calibrating_32768khz_rcosc">Calibrating the 32.768 kHz RC oscillator</a></span>). &nbsp; Calibration is usually taken care of by the Softdevice, but if you use an application without a Softdevice you need to enable calibration yourself.</p> <p>Here&#39;s an example where calibration is enabled without the Softdevice:</p> <p><a href="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/6201.SDK17.0.2_5F00_peripheral_5F00_rtc_5F00_w_5F00_rcosc.zip">devzone.nordicsemi.com/.../6201.SDK17.0.2_5F00_peripheral_5F00_rtc_5F00_w_5F00_rcosc.zip</a></p><div style="clear:both;"></div>