diff --git a/src/lib/core/datetime.h b/src/lib/core/datetime.h
index fcf1c7aea292859755c9608d214b9d8d2c02beed..af831e0a25899d62405ecd6cbfc8e9ef3af7dbf8 100644
--- a/src/lib/core/datetime.h
+++ b/src/lib/core/datetime.h
@@ -94,7 +94,7 @@ struct datetime {
 };
 
 /**
- * To be able to perform arithmetics on time intervals and receive
+ * To be able to perform arithmetic on time intervals and receive
  * deterministic results, we keep each component (i.e. years, months, weeks,
  * days, etc) separately from seconds.
  * We add/subtract interval components separately, and rebase upon resultant
@@ -216,9 +216,9 @@ datetime_parse_full(struct datetime *date, const char *str, size_t len,
  * @param str input text in relaxed ISO-8601 format (0-terminated)
  * @param len length of str buffer
  * @param[out] tzoffset return timezone offset if recognized
- * @param[out] tzindex return timzeon index if recognized
+ * @param[out] tzindex return timezone index if recognized
  * @retval Upon successful completion returns length of accepted
- *         substring. Returns 0 if text is not recognizable as timzeone.
+ *         substring. Returns 0 if text is not recognizable as timezone.
  *         Returns negative value is there is unaccepted timezone.
  * @sa datetime_parse_full()
  */
diff --git a/src/lua/datetime.lua b/src/lua/datetime.lua
index a3fd61ea5d7aea12bf9822a2124659543466fc44..c26e1d3aa8c696f4e396c7f095c5c28f2faca84e 100644
--- a/src/lua/datetime.lua
+++ b/src/lua/datetime.lua
@@ -7,7 +7,7 @@ local tz = require('timezones')
     values, where `dt` is a number of dates since Rata Die date (0001-01-01).
 
     `c-dt` uses 32-bit integer number to store `dt` values, so range of
-    suported dates is limited to dates from -5879610-06-22 (INT32_MIN) to
+    supported dates is limited to dates from -5879610-06-22 (INT32_MIN) to
     +5879611-07-11 (INT32_MAX).
 
     For better compactness of our typical data in MessagePack stream we shift
@@ -253,7 +253,7 @@ local function check_str_or_nil(s, message)
 end
 
 -- range may be of a form of pair {from, to} or
--- tuple {fom, to, -1 in extra}
+-- tuple {from, to, -1 in extra}
 -- -1 is a special value (so far) used for days only
 local function check_range(v, from, to, txt, extra)
     if type(v) ~= 'number' then