diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
index be3ae53e1e7558dcca9b46d79f96532306348712..ab29f55c76378eb5c97d1ac0d405e40a4c3f9e12 100644
--- a/openssl-sys/src/lib.rs
+++ b/openssl-sys/src/lib.rs
@@ -7,7 +7,7 @@ extern crate libc;
 #[cfg(target_os = "nacl")]
 extern crate libressl_pnacl_sys;
 
-use libc::{c_void, c_int, c_char, c_ulong, c_long, c_uint, c_uchar, size_t};
+use libc::{c_void, c_int, c_char, c_ulong, c_long, c_uint, c_uchar, size_t, FILE};
 use std::mem;
 use std::ptr;
 use std::sync::{Mutex, MutexGuard};
@@ -625,13 +625,16 @@ extern "C" {
     pub fn ASN1_INTEGER_set(dest: *mut ASN1_INTEGER, value: c_long) -> c_int;
     pub fn ASN1_STRING_type_new(ty: c_int) -> *mut ASN1_STRING;
     pub fn ASN1_TIME_free(tm: *mut ASN1_TIME);
+    pub fn ASN1_TIME_print(b: *mut BIO, tm: *const ASN1_TIME) -> c_int;
 
     pub fn BIO_ctrl(b: *mut BIO, cmd: c_int, larg: c_long, parg: *mut c_void) -> c_long;
     pub fn BIO_free_all(b: *mut BIO);
     pub fn BIO_new(type_: *const BIO_METHOD) -> *mut BIO;
+    pub fn BIO_new_fp(stream: *mut FILE, close_flag: c_int) -> *mut BIO;
     pub fn BIO_new_socket(sock: c_int, close_flag: c_int) -> *mut BIO;
     pub fn BIO_read(b: *mut BIO, buf: *mut c_void, len: c_int) -> c_int;
     pub fn BIO_write(b: *mut BIO, buf: *const c_void, len: c_int) -> c_int;
+    pub fn BIO_s_file() -> *const BIO_METHOD;
     pub fn BIO_s_mem() -> *const BIO_METHOD;
     pub fn BIO_new_mem_buf(buf: *const c_void, len: c_int) -> *mut BIO;
     pub fn BIO_set_flags(b: *mut BIO, flags: c_int);
diff --git a/openssl/Cargo.toml b/openssl/Cargo.toml
index d1d709a388c33b0a86e5728c9163930ba670e6ea..9c09aed62f844f7645c20c54f79d125998e11ec5 100644
--- a/openssl/Cargo.toml
+++ b/openssl/Cargo.toml
@@ -30,6 +30,7 @@ hmac_clone = ["openssl-sys/hmac_clone"]
 c_helpers = ["gcc"]
 x509_clone = ["c_helpers"]
 x509_generator_request = ["c_helpers"]
+x509_expiry = ["c_helpers"]
 ssl_context_clone = ["c_helpers"]
 hmac = ["c_helpers"]
 dh_from_params = ["c_helpers"]
diff --git a/openssl/src/asn1/mod.rs b/openssl/src/asn1/mod.rs
index 7d2097757020d5f33c16813d8b25abd203d25650..1eab9f041d99f96e9d6332a316d4cc382efd9e1a 100644
--- a/openssl/src/asn1/mod.rs
+++ b/openssl/src/asn1/mod.rs
@@ -1,15 +1,19 @@
 use libc::c_long;
-use std::ptr;
+use std::{ptr, fmt};
+use std::marker::PhantomData;
+use std::ops::Deref;
 
+use bio::MemBio;
 use ffi;
 use error::ErrorStack;
 
-pub struct Asn1Time(*mut ffi::ASN1_TIME);
+/// Corresponds to the ASN.1 structure Time defined in RFC5280
+pub struct Asn1Time(Asn1TimeRef<'static>);
 
 impl Asn1Time {
     /// Wraps existing ASN1_TIME and takes ownership
     pub unsafe fn from_ptr(handle: *mut ffi::ASN1_TIME) -> Asn1Time {
-        Asn1Time(handle)
+        Asn1Time(Asn1TimeRef::from_ptr(handle))
     }
 
     fn from_period(period: c_long) -> Result<Asn1Time, ErrorStack> {
@@ -25,6 +29,24 @@ impl Asn1Time {
     pub fn days_from_now(days: u32) -> Result<Asn1Time, ErrorStack> {
         Asn1Time::from_period(days as c_long * 60 * 60 * 24)
     }
+}
+
+impl Deref for Asn1Time {
+    type Target = Asn1TimeRef<'static>;
+
+    fn deref(&self) -> &Asn1TimeRef<'static> {
+        &self.0
+    }
+}
+
+/// A borrowed Asn1Time
+pub struct Asn1TimeRef<'a>(*mut ffi::ASN1_TIME, PhantomData<&'a ()>);
+
+impl<'a> Asn1TimeRef<'a> {
+    /// Creates a new `Asn1TimeRef` wrapping the provided handle.
+    pub unsafe fn from_ptr(handle: *mut ffi::ASN1_TIME) -> Asn1TimeRef<'a> {
+        Asn1TimeRef(handle, PhantomData)
+    }
 
     /// Returns the raw handle
     pub fn as_ptr(&self) -> *mut ffi::ASN1_TIME {
@@ -32,8 +54,19 @@ impl Asn1Time {
     }
 }
 
+impl<'a> fmt::Display for Asn1TimeRef<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mem_bio = try!(MemBio::new());
+        let as_str = unsafe {
+            try_ssl!(ffi::ASN1_TIME_print(mem_bio.as_ptr(), self.0));
+            String::from_utf8_unchecked(mem_bio.get_buf().to_owned())
+        };
+        write!(f, "{}", as_str)
+    }
+}
+
 impl Drop for Asn1Time {
     fn drop(&mut self) {
-        unsafe { ffi::ASN1_TIME_free(self.0) };
+        unsafe { ffi::ASN1_TIME_free(self.as_ptr()) };
     }
 }
diff --git a/openssl/src/c_helpers.c b/openssl/src/c_helpers.c
index 5d149553333fc2b650667865bd9c373ab906db84..6e6a5021f29824fa1821b2c05bff3987db8759da 100644
--- a/openssl/src/c_helpers.c
+++ b/openssl/src/c_helpers.c
@@ -15,6 +15,14 @@ STACK_OF(X509_EXTENSION) *rust_0_8_X509_get_extensions(X509 *x) {
     return x->cert_info ? x->cert_info->extensions : NULL;
 }
 
+ASN1_TIME* rust_0_8_X509_get_notAfter(X509 *x) {
+  return X509_get_notAfter(x);
+}
+
+ASN1_TIME* rust_0_8_X509_get_notBefore(X509 *x) {
+  return X509_get_notBefore(x);
+}
+
 DH *rust_0_8_DH_new_from_params(BIGNUM *p, BIGNUM *g, BIGNUM *q) {
     DH *dh;
 
diff --git a/openssl/src/c_helpers.rs b/openssl/src/c_helpers.rs
index 74ddb9ac799be2f22b3281e54e7539d776707878..d16c3125fbf4bd9ee554d330a46c4c55c04d58c9 100644
--- a/openssl/src/c_helpers.rs
+++ b/openssl/src/c_helpers.rs
@@ -6,7 +6,8 @@ extern "C" {
     pub fn rust_0_8_SSL_CTX_clone(cxt: *mut ffi::SSL_CTX);
     pub fn rust_0_8_X509_clone(x509: *mut ffi::X509);
     pub fn rust_0_8_X509_get_extensions(x: *mut ffi::X509) -> *mut ffi::stack_st_X509_EXTENSION;
-
+    pub fn rust_0_8_X509_get_notAfter(x: *mut ffi::X509) -> *mut ffi::ASN1_TIME;
+    pub fn rust_0_8_X509_get_notBefore(x: *mut ffi::X509) -> *mut ffi::ASN1_TIME;
     pub fn rust_0_8_HMAC_Init_ex(ctx: *mut ffi::HMAC_CTX, key: *const c_void, keylen: c_int, md: *const ffi::EVP_MD, impl_: *mut ffi::ENGINE) -> c_int;
     pub fn rust_0_8_HMAC_Final(ctx: *mut ffi::HMAC_CTX, output: *mut c_uchar, len: *mut c_uint) -> c_int;
     pub fn rust_0_8_HMAC_Update(ctx: *mut ffi::HMAC_CTX, input: *const c_uchar, len: c_uint) -> c_int;
diff --git a/openssl/src/error.rs b/openssl/src/error.rs
index 5fa542c2cf53ce2baeedbee77e6bc34931a810fb..cc89b5db708eba426126f21a71bb1985f770a20e 100644
--- a/openssl/src/error.rs
+++ b/openssl/src/error.rs
@@ -54,6 +54,12 @@ impl From<ErrorStack> for io::Error {
     }
 }
 
+impl From<ErrorStack> for fmt::Error {
+    fn from(_: ErrorStack) -> fmt::Error {
+        fmt::Error
+    }
+}
+
 /// An error reported from OpenSSL.
 pub struct Error(c_ulong);
 
diff --git a/openssl/src/x509/mod.rs b/openssl/src/x509/mod.rs
index 0cc0eca7c39372e7b4338fa219f9f3b7737eef3f..1319b75c7c567b6e05d4b086b5612c7d60119fe7 100644
--- a/openssl/src/x509/mod.rs
+++ b/openssl/src/x509/mod.rs
@@ -11,6 +11,9 @@ use std::marker::PhantomData;
 
 use HashTypeInternals;
 use asn1::Asn1Time;
+#[cfg(feature = "x509_expiry")]
+use asn1::Asn1TimeRef;
+
 use bio::{MemBio, MemBioSlice};
 use crypto::hash;
 use crypto::hash::Type as HashType;
@@ -433,6 +436,28 @@ impl<'a> X509Ref<'a> {
         }
     }
 
+    /// Returns certificate Not After validity period.
+    /// Requires the `x509_expiry` feature.
+    #[cfg(feature = "x509_expiry")]
+    pub fn not_after<'b>(&'b self) -> Asn1TimeRef<'b> {
+        unsafe {
+            let date = ::c_helpers::rust_0_8_X509_get_notAfter(self.0);
+            assert!(!date.is_null());
+            Asn1TimeRef::from_ptr(date)
+        }
+    }
+
+    /// Returns certificate Not Before validity period.
+    /// Requires the `x509_expiry` feature.
+    #[cfg(feature = "x509_expiry")]
+    pub fn not_before<'b>(&'b self) -> Asn1TimeRef<'b> {
+        unsafe {
+            let date = ::c_helpers::rust_0_8_X509_get_notBefore(self.0);
+            assert!(!date.is_null());
+            Asn1TimeRef::from_ptr(date)
+        }
+    }
+
     /// Writes certificate as PEM
     pub fn to_pem(&self) -> Result<Vec<u8>, ErrorStack> {
         let mem_bio = try!(MemBio::new());
diff --git a/openssl/src/x509/tests.rs b/openssl/src/x509/tests.rs
index 43add8968fc15612beec59f19e4eca259bca21f0..eac08941f6c909a478730ab26b5cb438c72001a5 100644
--- a/openssl/src/x509/tests.rs
+++ b/openssl/src/x509/tests.rs
@@ -92,6 +92,18 @@ fn test_cert_loading() {
     assert_eq!(fingerprint, hash_vec);
 }
 
+#[test]
+#[cfg(feature = "x509_expiry")]
+fn test_cert_issue_validity() {
+    let cert = include_bytes!("../../test/cert.pem");
+    let cert = X509::from_pem(cert).ok().expect("Failed to load PEM");
+    let not_before = cert.not_before().to_string();
+    let not_after = cert.not_after().to_string();
+
+    assert_eq!(not_before, "Aug 14 17:00:03 2016 GMT");
+    assert_eq!(not_after, "Aug 12 17:00:03 2026 GMT");
+}
+
 #[test]
 fn test_save_der() {
     let cert = include_bytes!("../../test/cert.pem");
diff --git a/openssl/test/run.sh b/openssl/test/run.sh
index b94818378365b35e7638f7eb0f5574637463f08d..2c2473b1aaeab885442a531eaa80f5c8daf5a2d7 100755
--- a/openssl/test/run.sh
+++ b/openssl/test/run.sh
@@ -4,7 +4,7 @@ set -e
 MAIN_TARGETS=https://static.rust-lang.org/dist
 
 if [ "$TEST_FEATURES" == "true" ]; then
-    FEATURES="tlsv1_2 tlsv1_1 dtlsv1 dtlsv1_2 sslv3 aes_xts aes_ctr npn alpn rfc5114 ecdh_auto pkcs5_pbkdf2_hmac x509_clone ssl_context_clone x509_generator_request hmac hmac_clone dh_from_params"
+    FEATURES="tlsv1_2 tlsv1_1 dtlsv1 dtlsv1_2 sslv3 aes_xts aes_ctr npn alpn rfc5114 ecdh_auto pkcs5_pbkdf2_hmac x509_clone ssl_context_clone x509_generator_request hmac hmac_clone dh_from_params x509_expiry"
 fi
 
 if [ "$TRAVIS_OS_NAME" != "osx" ]; then