diff --git a/cpu/lpc23xx/periph/rtc.c b/cpu/lpc23xx/periph/rtc.c
index 15d3fc6b04..0820ada8b3 100644
--- a/cpu/lpc23xx/periph/rtc.c
+++ b/cpu/lpc23xx/periph/rtc.c
@@ -57,7 +57,7 @@ void rtc_init(void)
      * after cold boot or external reset.
      */
     if ((RSIR == RSIR_POR) || (RSIR == (RSIR_POR | RSIR_EXTR))) {
-        struct tm localt = { .tm_year = 70 };
+        struct tm localt = { .tm_year = RIOT_EPOCH - 1900 };
         rtc_set_time(&localt);
     }
 
diff --git a/cpu/sam0_common/periph/rtc_rtt.c b/cpu/sam0_common/periph/rtc_rtt.c
index 5e62426b9a..caa3369def 100644
--- a/cpu/sam0_common/periph/rtc_rtt.c
+++ b/cpu/sam0_common/periph/rtc_rtt.c
@@ -62,9 +62,10 @@ static rtc_state_t alarm_cb;
 static rtc_state_t overflow_cb;
 
 /* At 1Hz, RTC goes till 63 years (2^5, see 17.8.22 in datasheet)
-* reference_year is set to 100 (offset) to be in our current time (2000)
-* Thanks to this, the user will be able to set time in 2000's*/
-static uint16_t reference_year = 100;
+ * struct tm younts the year since 1900, use the difference to RIOT_EPOCH
+ * as an offset so the user can set years in RIOT_EPOCH + 63
+ */
+static uint16_t reference_year = RIOT_EPOCH - 1900;
 
 static void _wait_syncbusy(void)
 {
diff --git a/cpu/stm32/periph/rtc_all.c b/cpu/stm32/periph/rtc_all.c
index 8062e0e401..44285e3892 100644
--- a/cpu/stm32/periph/rtc_all.c
+++ b/cpu/stm32/periph/rtc_all.c
@@ -163,9 +163,8 @@
 #error "rtc: unable to determine RTC SYNC and ASYNC prescalers from LSI value"
 #endif
 
-/* struct tm counts years since 1900 but RTC has only two-digit year hence the
- * offset of 100 years. */
-#define YEAR_OFFSET         (100)
+/* struct tm counts years since 1900 but RTC has only two-digit year, hence the offset */
+#define YEAR_OFFSET         (RIOT_EPOCH - 1900)
 
 /* Use a magic number to determine the initial RTC source. This will be used
    to know if a reset of the RTC is required at initialization. */
@@ -273,7 +272,7 @@ int rtc_set_time(struct tm *time)
 
     rtc_unlock();
 
-    RTC->DR = (val2bcd((time->tm_year % 100), RTC_DR_YU_Pos, DR_Y_MASK) |
+    RTC->DR = (val2bcd((time->tm_year - YEAR_OFFSET), RTC_DR_YU_Pos, DR_Y_MASK) |
                val2bcd(time->tm_mon + 1,  RTC_DR_MU_Pos, DR_M_MASK) |
                val2bcd(time->tm_mday, RTC_DR_DU_Pos, DR_D_MASK));
     RTC->TR = (val2bcd(time->tm_hour, RTC_TR_HU_Pos, TR_H_MASK) |
diff --git a/drivers/include/periph/rtc.h b/drivers/include/periph/rtc.h
index 4885996be9..5c21822ce1 100644
--- a/drivers/include/periph/rtc.h
+++ b/drivers/include/periph/rtc.h
@@ -46,6 +46,18 @@
 extern "C" {
 #endif
 
+#if !defined(RIOT_EPOCH) || DOXYGEN
+/**
+ * @brief Earliest year of the RTC
+ *
+ * 01.01.$RIOT_EPOCH will be the reset value of the RTC if supported.
+ *
+ * Internal RTC helper functions such as @see rtc_mktime and @see rtc_localtime
+ * will not work on dates earlier than that.
+ */
+#define RIOT_EPOCH (2020)
+#endif
+
 /**
  * @brief Signature for alarm Callback
  *
diff --git a/drivers/periph_common/rtc.c b/drivers/periph_common/rtc.c
index 3968c3aec8..e12dce5d94 100644
--- a/drivers/periph_common/rtc.c
+++ b/drivers/periph_common/rtc.c
@@ -31,10 +31,6 @@
 #define HOUR    (60U * MINUTE)
 #define DAY     (24U * HOUR)
 
-#ifndef RIOT_EPOCH
-#define RIOT_EPOCH (2020)
-#endif
-
 /*
  * The rules here are (to be checked in that explicit order):
  *  1. If the year is not a multiple of four, it is not a leap year.