diff --git a/README.md b/README.md
index 7bfe59a..b9c9b6d 100644
--- a/README.md
+++ b/README.md
@@ -55,7 +55,7 @@ repositories {
 
 ``` groovy
 dependencies {
-    compile "ch.poole:OpeningHoursParser:0.16.1"
+    compile "ch.poole:OpeningHoursParser:0.17.1"
 }
 ```
 
diff --git a/build.gradle b/build.gradle
index dd4bb9f..a52a8be 100644
--- a/build.gradle
+++ b/build.gradle
@@ -16,7 +16,7 @@ apply plugin: 'maven-publish'
 apply plugin: "jacoco"
 
 
-version = '0.17.0'
+version = '0.17.1'
 sourceCompatibility = 1.8
 targetCompatibility = 1.8
 
diff --git a/src/main/java/ch/poole/openinghoursparser/OpeningHoursParser.jj b/src/main/java/ch/poole/openinghoursparser/OpeningHoursParser.jj
index 2570980..a51abe9 100644
--- a/src/main/java/ch/poole/openinghoursparser/OpeningHoursParser.jj
+++ b/src/main/java/ch/poole/openinghoursparser/OpeningHoursParser.jj
@@ -25,12 +25,15 @@
 
 package ch.poole.openinghoursparser;
  
import java.util.ArrayList;
import java.util.Collections;
-import java.util.Locale;
import java.io.ByteArrayInputStream;

public class OpeningHoursParser
{
+import java.util.Locale;
import java.io.ByteArrayInputStream;
+
+import ch.poole.openinghoursparser.Util;

public class OpeningHoursParser
{
   static int TWELVEHOURS = 12*60;
   
   boolean strict = false;
   enum AMPM { AM, PM };
-  boolean monthOnly = false;
}

PARSER_END(OpeningHoursParser)

SKIP :
{
  "\r"
| "\n"
| " "
| "\t"
+  boolean monthOnly = false;
}
+
PARSER_END(OpeningHoursParser)

SKIP :
{
  "\r"
| "\n"
| " "
| "\t"
 | "\u200A"
 | "\u2009"
 | "\u00A0"
@@ -91,9 +94,9 @@ TOKEN :
 {
  < TO : " to " >
 }

/**
  * match a number between 1 and 5
- */
Token one2five() :
{
  Token n = null;
}
{
  LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 1 && Integer.parseInt(getToken(1).image) <= 5 })
  n = < NUMBER >
  {
    return n;
  }
}

/**
+ */
Token one2five() :
{
  Token n = null;
}
{
  LOOKAHEAD({ getToken(1).kind == NUMBER && Util.between(getToken(1).image, 1, 5) })
  n = < NUMBER >
  {
    return n;
  }
}

/**
  * match a positive number larger than 1
- */
Token number() :
{
  Token n = null;
}
{
  LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 1 })
  n = < NUMBER >
  {
    return n;
  }
}

/**
+ */
Token number() :
{
  Token n = null;
}
{
  LOOKAHEAD({ getToken(1).kind == NUMBER && Util.equalsOrMore(getToken(1).image, 1) })
  n = < NUMBER >
  {
    return n;
  }
}

/**
  * Match a comment.
  */
String comment() :
{
  StringBuilder builder = new StringBuilder();
}
{
  < QUOTE >
  (
    getChar(builder)
  )*
  < ENDQUOTE >
  {
    return builder.toString();
  }
}

/**
  * Match char inside quoted string.
@@ -103,7 +106,7 @@ TOKEN :
 /**
  * returns a number if between 0 and 24
  * uses semantic lookahead
- */
Token hours() :
{
  Token h = null;
}
{
  LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 0 && Integer.parseInt(getToken(1).image) <= 24 })
  h = < NUMBER >
  {
    return h;
  }
}
+ */
Token hours() :
{
  Token h = null;
}
{
  LOOKAHEAD({ getToken(1).kind == NUMBER && Util.between(getToken(1).image, 0, 24) })
  h = < NUMBER >
  {
    return h;
  }
}
 /**
  * returns the total number of minutes for a time of the form hh:00 or just hh
  *
@@ -166,7 +169,7 @@ AMPM ampm() :
 /**
  * returns the total number of minutes for a time of the form hh:00 or just hh with hh up to 48 
  */
int extendedtime() :
{
  Token h = null;
  Token m = null;
  int result = 0;
-  AMPM ampm = null;
}
{
  (
    LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 0 && Integer.parseInt(getToken(1).image) <= 48 })
    h = < NUMBER >
  )
  (
    m = < MINUTES >
    {
+  AMPM ampm = null;
}
{
  (
    LOOKAHEAD({ getToken(1).kind == NUMBER && Util.between(getToken(1).image, 0, 48) })
    h = < NUMBER >
  )
  (
    m = < MINUTES >
    {
       if (strict && (m.image.length() < 3 || !m.image.startsWith(":"))) {
         ParseException pex = new ParseException("Invalid minutes at " + token.next.beginLine + ", column " + token.next.beginColumn);
 	    pex.currentToken = token;
@@ -336,7 +339,7 @@ WeekDayRange weekday_range() :
{
  String startDay = null;
  String endDay = nul
     return mdr;
   }
 }
-
int daynum() :
{
  Token n = null;
}
{
  (
    LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 1 && Integer.parseInt(getToken(1).image) <= 31 })
    n = < NUMBER >
  )
  {
    return Integer.parseInt(n.image);
  }
}
+
int daynum() :
{
  Token n = null;
}
{
  (
    LOOKAHEAD({ getToken(1).kind == NUMBER && Util.between(getToken(1).image, 1, 31) })
    n = < NUMBER >
  )
  {
    return Integer.parseInt(n.image);
  }
}
 
 int year() :
 {
@@ -344,7 +347,7 @@ int year() :
 }
 {
   (
-    LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 1900})
+    LOOKAHEAD({ getToken(1).kind == NUMBER && Util.equalsOrMore(getToken(1).image, 1900)})
     n = < NUMBER >
   )
   {
@@ -486,7 +489,7 @@ int year() :
       return result;
     }
   )
-}

int weeknum() :
{
  Token n = null;
}
{
  (
    LOOKAHEAD({ getToken(1).kind == NUMBER && Integer.parseInt(getToken(1).image) >= 1 && Integer.parseInt(getToken(1).image) <= 54 })
    n = < NUMBER >
  )
  {
    return Integer.parseInt(n.image);
  }
}

WeekRange week_range() :
{
  WeekRange wr = new WeekRange();
  Token w = null;
  Token w1 = null;
+}

int weeknum() :
{
  Token n = null;
}
{
  (
    LOOKAHEAD({ getToken(1).kind == NUMBER && Util.between(getToken(1).image, 1, 54) })
    n = < NUMBER >
  )
  {
    return Integer.parseInt(n.image);
  }
}

WeekRange week_range() :
{
  WeekRange wr = new WeekRange();
  Token w = null;
  Token w1 = null;
   Token to = null;
}
{
  wr.startWeek = weeknum()
  (
    (
      < HYPHEN > | (to = < TO >)
     )
     (
diff --git a/src/main/java/ch/poole/openinghoursparser/Util.java b/src/main/java/ch/poole/openinghoursparser/Util.java
index 5f99eb6..9984b70 100644
--- a/src/main/java/ch/poole/openinghoursparser/Util.java
+++ b/src/main/java/ch/poole/openinghoursparser/Util.java
@@ -79,7 +79,7 @@ public static List<ArrayList<Rule>> getMergeableRules(List<Rule> rules) {
     public static String rulesToOpeningHoursString(@NotNull List<Rule> rules) {
         return rulesToOpeningHoursString(rules, false);
     }
-       
+
     /**
      * Generate an OH string from rules
      * 
@@ -180,4 +180,37 @@ static <T extends Copy<?>> List<T> copyList(List<T> l) {
         }
         return r;
     }
+
+    /**
+     * Make a safe comparison catching parse errors
+     * 
+     * @param token the current token
+     * @param lower lower bounds
+     * @return true if greater or equals to limit and is an int
+     */
+    static boolean equalsOrMore(@NotNull String token, int lower) {
+        try {
+            int temp = Integer.parseInt(token);
+            return temp >= lower;
+        } catch (NumberFormatException nfe) {
+            return false;
+        }
+    }
+
+    /**
+     * Make a safe comparison catching parse errors
+     * 
+     * @param token the current token
+     * @param lower lower bounds
+     * @param upper upper bounds
+     * @return true if in bounds and is an int
+     */
+    static boolean between(@NotNull String token, int lower, int upper) {
+        try {
+            int temp = Integer.parseInt(token);
+            return temp >= lower && temp <= upper;
+        } catch (NumberFormatException nfe) {
+            return false;
+        }
+    }
 }
diff --git a/test-data/oh.txt-result b/test-data/oh.txt-result
index b3fd73d..78d2ccb 100644
--- a/test-data/oh.txt-result
+++ b/test-data/oh.txt-result
@@ -8989,7 +8989,7 @@
 1
 1
 1
-2
+1
 1
 1
 0	02:00-09:00
@@ -11083,7 +11083,7 @@
 1
 0	08:00-10:30,11:00-14:30; Fr off
 0	08:00-21:00
-2
+1
 0	08:00-10:00
 0	08:00-10:00,04:00-19:00
 1
diff --git a/test-data/oh.txt-result-strict b/test-data/oh.txt-result-strict
index dee129a..b56a2eb 100644
--- a/test-data/oh.txt-result-strict
+++ b/test-data/oh.txt-result-strict
@@ -8989,7 +8989,7 @@
 1
 1
 1
-2
+1
 1
 1
 1
@@ -11083,7 +11083,7 @@
 1
 1
 1
-2
+1
 1
 1
 1