diff --git a/README.md b/README.md
index 063a852d..891e8ba2 100644
--- a/README.md
+++ b/README.md
@@ -157,6 +157,7 @@ Here are some examples of conditions you can use:
 | `len([BODY].data) < 5`       | Array at JSONPath `$.data` has less than 5 elements     | `{"data":[{"id":1}]}`      |  |
 | `len([BODY].name) == 8`      | String at JSONPath `$.name` has a length of 8           | `{"name":"john.doe"}`      | `{"name":"bob"}` |
 | `[BODY].name == pat(john*)`  | String at JSONPath `$.name` matches pattern `john*`     | `{"name":"john.doe"}`      | `{"name":"bob"}` |
+| `[CERTIFICATE_EXPIRATION] > 48h` | Certificate expiration is more than 48h away        | `{"name":"john.doe"}`      | `{"name":"bob"}` |
 
 
 #### Placeholders
@@ -168,7 +169,7 @@ Here are some examples of conditions you can use:
 | `[IP]`                     | Resolves into the IP of the target host                         | 192.168.0.232
 | `[BODY]`                   | Resolves into the response body. Supports JSONPath.             | `{"name":"john.doe"}`
 | `[CONNECTED]`              | Resolves into whether a connection could be established         | `true`
-| `[CERTIFICATE_EXPIRATION]` | Resolves into the duration before certificate expiration, in ms | 4461677039, 0 (if not using HTTPS)
+| `[CERTIFICATE_EXPIRATION]` | Resolves into the duration before certificate expiration        | `24h`, `48h`, 0 (if not using HTTPS)
 
 
 #### Functions
diff --git a/core/condition.go b/core/condition.go
index 964416fd..36cc9bf3 100644
--- a/core/condition.go
+++ b/core/condition.go
@@ -2,11 +2,13 @@ package core
 
 import (
 	"fmt"
-	"github.com/TwinProduction/gatus/jsonpath"
-	"github.com/TwinProduction/gatus/pattern"
 	"log"
 	"strconv"
 	"strings"
+	"time"
+
+	"github.com/TwinProduction/gatus/jsonpath"
+	"github.com/TwinProduction/gatus/pattern"
 )
 
 const (
@@ -185,7 +187,9 @@ func sanitizeAndResolveNumerical(list []string, result *Result) []int64 {
 	var sanitizedNumbers []int64
 	sanitizedList := sanitizeAndResolve(list, result)
 	for _, element := range sanitizedList {
-		if number, err := strconv.ParseInt(element, 10, 64); err != nil {
+		if duration, err := time.ParseDuration(element); duration != 0 && err == nil {
+			sanitizedNumbers = append(sanitizedNumbers, duration.Milliseconds())
+		} else if number, err := strconv.ParseInt(element, 10, 64); err != nil {
 			// Default to 0 if the string couldn't be converted to an integer
 			sanitizedNumbers = append(sanitizedNumbers, 0)
 		} else {
diff --git a/core/condition_test.go b/core/condition_test.go
index d4e929df..3aa3fc6d 100644
--- a/core/condition_test.go
+++ b/core/condition_test.go
@@ -60,7 +60,27 @@ func TestCondition_evaluateWithResponseTimeUsingLessThan(t *testing.T) {
 	}
 }
 
+func TestCondition_evaluateWithResponseTimeUsingLessThanDuration(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] < 1s")
+	result := &Result{Duration: time.Millisecond * 50}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestCondition_evaluateWithResponseTimeUsingLessThanInvalid(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] < potato")
+	result := &Result{Duration: time.Millisecond * 50}
+	condition.evaluate(result)
+	if result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have failed because the condition has an invalid numerical value that should've automatically resolved to 0", condition)
+	}
+}
+
 func TestCondition_evaluateWithResponseTimeUsingGreaterThan(t *testing.T) {
+	// Not exactly sure why you'd want to have a condition that checks if the response time is too fast,
+	// but hey, who am I to judge?
 	condition := Condition("[RESPONSE_TIME] > 500")
 	result := &Result{Duration: time.Millisecond * 750}
 	condition.evaluate(result)
@@ -69,6 +89,15 @@ func TestCondition_evaluateWithResponseTimeUsingGreaterThan(t *testing.T) {
 	}
 }
 
+func TestCondition_evaluateWithResponseTimeUsingGreaterThanDuration(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] > 1s")
+	result := &Result{Duration: time.Second * 2}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
 func TestCondition_evaluateWithResponseTimeUsingGreaterThanOrEqualTo(t *testing.T) {
 	condition := Condition("[RESPONSE_TIME] >= 500")
 	result := &Result{Duration: time.Millisecond * 500}
@@ -320,7 +349,7 @@ func TestCondition_evaluateWithUnsetCertificateExpiration(t *testing.T) {
 	}
 }
 
-func TestCondition_evaluateWithCertificateExpirationGreaterThan(t *testing.T) {
+func TestCondition_evaluateWithCertificateExpirationGreaterThanNumerical(t *testing.T) {
 	acceptable := (time.Hour * 24 * 28).Milliseconds()
 	condition := Condition("[CERTIFICATE_EXPIRATION] > " + strconv.FormatInt(acceptable, 10))
 	result := &Result{CertificateExpiration: time.Hour * 24 * 60}
@@ -330,7 +359,7 @@ func TestCondition_evaluateWithCertificateExpirationGreaterThan(t *testing.T) {
 	}
 }
 
-func TestCondition_evaluateWithCertificateExpirationGreaterThanFailure(t *testing.T) {
+func TestCondition_evaluateWithCertificateExpirationGreaterThanNumericalFailure(t *testing.T) {
 	acceptable := (time.Hour * 24 * 28).Milliseconds()
 	condition := Condition("[CERTIFICATE_EXPIRATION] > " + strconv.FormatInt(acceptable, 10))
 	result := &Result{CertificateExpiration: time.Hour * 24 * 14}
@@ -339,3 +368,21 @@ func TestCondition_evaluateWithCertificateExpirationGreaterThanFailure(t *testin
 		t.Errorf("Condition '%s' should have been a failure", condition)
 	}
 }
+
+func TestCondition_evaluateWithCertificateExpirationGreaterThanDuration(t *testing.T) {
+	condition := Condition("[CERTIFICATE_EXPIRATION] > 12h")
+	result := &Result{CertificateExpiration: 24 * time.Hour}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestCondition_evaluateWithCertificateExpirationGreaterThanDurationFailure(t *testing.T) {
+	condition := Condition("[CERTIFICATE_EXPIRATION] > 48h")
+	result := &Result{CertificateExpiration: 24 * time.Hour}
+	condition.evaluate(result)
+	if result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a failure", condition)
+	}
+}