diff --git a/modules/atto/shared/src/main/scala/cron4s/atto/Parser.scala b/modules/atto/shared/src/main/scala/cron4s/atto/Parser.scala
index 8b7ea94b..538fdcb1 100644
--- a/modules/atto/shared/src/main/scala/cron4s/atto/Parser.scala
+++ b/modules/atto/shared/src/main/scala/cron4s/atto/Parser.scala
@@ -20,6 +20,8 @@ import _root_.atto.{Parser => AttoParser, _}
 import atto.Atto._
 import cats.implicits._
 
+import java.util.Locale
+
 object Parser extends cron4s.parser.Parser {
 
   import cron4s.parser._
@@ -45,7 +47,7 @@ object Parser extends cron4s.parser.Parser {
 
   private val sexagesimal: AttoParser[Int] = oneOrTwoDigitsPositiveInt.filter(x => x >= 0 && x < 60)
 
-  private val literal: AttoParser[String] = takeWhile1(x => x != ' ' && x != '-')
+  private val literal: AttoParser[String] = takeWhile1(x => x != ' ' && x != '-' && x != ',')
 
   private val hyphen: AttoParser[Char]       = elem(_ == '-', "hyphen")
   private val comma: AttoParser[Char]        = elem(_ == ',', "comma")
@@ -95,7 +97,7 @@ object Parser extends cron4s.parser.Parser {
     oneOrTwoDigitsPositiveInt.filter(x => (x >= 0) && (x <= 6)).map(ConstNode(_))
 
   private[this] val textualDaysOfWeek: AttoParser[ConstNode] =
-    literal.filter(DaysOfWeek.textValues.contains).map { value =>
+    literal.map(_.toLowerCase(Locale.US)).filter(DaysOfWeek.textValues.contains).map { value =>
       val index = DaysOfWeek.textValues.indexOf(value)
       ConstNode(index, Some(value))
     }
diff --git a/modules/parserc/shared/src/main/scala/cron4s/parsing/parser.scala b/modules/parserc/shared/src/main/scala/cron4s/parsing/parser.scala
index b972b628..31e26514 100644
--- a/modules/parserc/shared/src/main/scala/cron4s/parsing/parser.scala
+++ b/modules/parserc/shared/src/main/scala/cron4s/parsing/parser.scala
@@ -19,6 +19,7 @@ package parsing
 
 import cron4s.parser._
 
+import java.util.Locale
 import scala.util.parsing.input._
 import scala.util.parsing.combinator._
 
@@ -87,7 +88,7 @@ object CronParser extends Parsers with BaseParser {
     decimal.filter(_ < 7).map(ConstNode(_))
 
   private[this] val textualDaysOfWeek =
-    literal.filter(DaysOfWeek.textValues.contains).map { value =>
+    literal.map(_.toLowerCase(Locale.US)).filter(DaysOfWeek.textValues.contains).map { value =>
       val index = DaysOfWeek.textValues.indexOf(value)
       ConstNode(index, Some(value))
     }
diff --git a/tests/shared/src/test/scala/cron4s/CronSpec.scala b/tests/shared/src/test/scala/cron4s/CronSpec.scala
index 7d7efa47..6ed01e45 100644
--- a/tests/shared/src/test/scala/cron4s/CronSpec.scala
+++ b/tests/shared/src/test/scala/cron4s/CronSpec.scala
@@ -26,12 +26,12 @@ import org.scalatest.prop.TableDrivenPropertyChecks
 
 import scala.util.{Failure, Success}
 import org.scalatest.prop.TableFor3
+import CronField._
 
 /**
   * Created by alonsodomin on 12/04/2017.
   */
 object CronSpec extends TableDrivenPropertyChecks {
-  import CronField._
 
   final val AllEachExpr  = "* * * * * *"
   final val AnyDaysExpr  = "* * * ? * ?"
@@ -95,7 +95,8 @@ object CronSpec extends TableDrivenPropertyChecks {
     "* 0 0,12 1 */2 *",
     "0 0,5,10,15,20,25,30,35,40,45,50,55 * * * *",
     "0 1 2-4 * 4,5,6 */3",
-    "1 5 4 * * mon-2,sun"
+    "1 5 4 * * mon-2,sun",
+    "0 0 * ? * MON-WED,FRI-SUN"
   )
 }
 
@@ -132,4 +133,20 @@ trait CronSpec extends Matchers { this: AnyFlatSpec =>
     cron.unsafeParse(exprStr) shouldBe ValidExpr
   }
 
+  it should "parse complexe day express" in {
+    val value1 = cron("0 0 * ? * MON-WED,FRI-SUN")
+    value1 shouldBe Right(
+      CronExpr(
+        ConstNode[Second](0),
+        ConstNode[Minute](0),
+        EachNode[Hour],
+        AnyNode[DayOfMonth],
+        EachNode[Month],
+        SeveralNode(
+          BetweenNode[DayOfWeek](ConstNode(0), ConstNode(2)),
+          BetweenNode[DayOfWeek](ConstNode(4), ConstNode(6))
+        )
+      )
+    )
+  }
 }