diff --git a/files/data-mw/l10n/Calendar/de.yaml b/files/data-mw/l10n/Calendar/de.yaml
index 3c6b672dd2..6d83cd2aad 100644
--- a/files/data-mw/l10n/Calendar/de.yaml
+++ b/files/data-mw/l10n/Calendar/de.yaml
@@ -57,4 +57,10 @@ weekday3: "Tirdas"
 weekday4: "Middas"
 weekday5: "Turdas"
 weekday6: "Fredas"
-weekday7: "Loredas"
\ No newline at end of file
+weekday7: "Loredas"
+
+# In German, there are usually no "a.m."/"p.m." shenanigans going on.
+# In case of ambiguity, "vormittags" ("mornings") and "nachmittags" ("in the afternoon") are used.
+am: "vormittags"
+pm: "nachmittags"
+day: "Tag"
diff --git a/files/data-mw/l10n/Calendar/en.yaml b/files/data-mw/l10n/Calendar/en.yaml
index b8c850281c..5fea9d8971 100644
--- a/files/data-mw/l10n/Calendar/en.yaml
+++ b/files/data-mw/l10n/Calendar/en.yaml
@@ -37,3 +37,7 @@ weekday4: "Middas"
 weekday5: "Turdas"
 weekday6: "Fredas"
 weekday7: "Loredas"
+
+am: "a.m."
+pm: "p.m."
+day: "Day"
diff --git a/files/data-mw/l10n/Calendar/ru.yaml b/files/data-mw/l10n/Calendar/ru.yaml
index 95828e1e6b..f79ada8a03 100644
--- a/files/data-mw/l10n/Calendar/ru.yaml
+++ b/files/data-mw/l10n/Calendar/ru.yaml
@@ -38,3 +38,7 @@ weekday4: "Миддас"
 weekday5: "Турдас"
 weekday6: "Фредас"
 weekday7: "Лордас"
+
+am: "д.п."
+pm: "п.п."
+day: "День"
diff --git a/files/data-mw/l10n/Calendar/sv.yaml b/files/data-mw/l10n/Calendar/sv.yaml
index 7aecb93455..1a168d1ad6 100644
--- a/files/data-mw/l10n/Calendar/sv.yaml
+++ b/files/data-mw/l10n/Calendar/sv.yaml
@@ -1,7 +1,15 @@
 # source: https://en.uesp.net/wiki/Lore:Calendar
 
-# Sv: Ingen vits att översätta namn på månader och dagar till svenska när inte spelets innehåll finns på svenska. Det lär mest bara förvirra. Därför finns bara dateFormat i denna fil.
+# Sv: Ingen vits att översätta namn på månader och dagar till svenska när inte spelets innehåll finns på svenska. Det lär mest bara förvirra.
+# Därför finns bara dateFormat, am, pm och day i denna fil.
 
-# En: No use translating names on months and weekdays to Swedish when the game's content isn't in Swedish. It will probably just confuse people. Therefore, only dateFormat is present in this file.
+# En: No use translating names on months and weekdays to Swedish when the game's content isn't in Swedish. It will probably just confuse people.
+# Therefore, only dateFormat, am, pm and day are present in this file.
 
 dateFormat: "dag {day} av {monthInGenitive} år {year, number, :: group-off}"
+
+# In Swedish, as with German, we don't use AM/PM but instead a 24h clock.
+# But instead of that, we could use "förmiddag" and "eftermiddag", which is basically "morning" and "afternoon"
+am: "förmiddag"
+pm: "eftermiddag"
+day: "Dag"
diff --git a/files/data/CMakeLists.txt b/files/data/CMakeLists.txt
index 662f00fd84..4b70a722f2 100644
--- a/files/data/CMakeLists.txt
+++ b/files/data/CMakeLists.txt
@@ -22,7 +22,10 @@ set(BUILTIN_DATA_FILES
     fonts/MysticCardsFontLicense.txt
 
     # Month names and date formatting
+    l10n/Calendar/de.yaml
     l10n/Calendar/en.yaml
+    l10n/Calendar/ru.yaml
+    l10n/Calendar/sv.yaml
 
     # Generic UI messages that can be reused by mods
     l10n/Interface/de.yaml
@@ -37,7 +40,9 @@ set(BUILTIN_DATA_FILES
     l10n/OMWCamera/ru.yaml
     l10n/OMWCamera/sv.yaml
     l10n/OMWCamera/fr.yaml
+    l10n/OMWControls/de.yaml
     l10n/OMWControls/en.yaml
+    l10n/OMWControls/fr.yaml
     l10n/OMWControls/ru.yaml
     l10n/OMWControls/sv.yaml
 
diff --git a/files/data/l10n/Calendar/ru.yaml b/files/data/l10n/Calendar/ru.yaml
new file mode 100644
index 0000000000..16a80e47bd
--- /dev/null
+++ b/files/data/l10n/Calendar/ru.yaml
@@ -0,0 +1,40 @@
+month1: "январь"
+month2: "февраль"
+month3: "март"
+month4: "апрель"
+month5: "май"
+month6: "июнь"
+month7: "июль"
+month8: "август"
+month9: "сентябрь"
+month10: "октябрь"
+month11: "ноябрь"
+month12: "декабрь"
+
+monthInGenitive1: "января"
+monthInGenitive2: "февраля"
+monthInGenitive3: "марта"
+monthInGenitive4: "апреля"
+monthInGenitive5: "мая"
+monthInGenitive6: "июня"
+monthInGenitive7: "июля"
+monthInGenitive8: "августа"
+monthInGenitive9: "сентября"
+monthInGenitive10: "октября"
+monthInGenitive11: "ноября"
+monthInGenitive12: "декабря"
+
+# Example: 1 января 1970
+dateFormat: "{day} {monthInGenitive} {year, number, :: group-off}"
+
+weekday1: "воскресенье"
+weekday2: "понедельник"
+weekday3: "вторник"
+weekday4: "среда"
+weekday5: "четверг"
+weekday6: "пятница"
+weekday7: "суббота"
+
+am: "д.п."
+pm: "п.п."
+day: "День"
diff --git a/files/data/l10n/Calendar/sv.yaml b/files/data/l10n/Calendar/sv.yaml
index 858e586412..59807e41a9 100644
--- a/files/data/l10n/Calendar/sv.yaml
+++ b/files/data/l10n/Calendar/sv.yaml
@@ -47,4 +47,4 @@ weekday7: "lördag"
 # But instead of that, we could use "förmiddag" and "eftermiddag", which is basically "morning" and "afternoon"
 am: "förmiddag"
 pm: "eftermiddag"
-day: "dag"
+day: "Dag"