Android KeyStore : Failed to generate self-signed certificate , invalid date string

I 'm trying to create keyPair using android Keystore following my code :

Calendar start = Calendar.getInstance();
                Calendar end = Calendar.getInstance();
                end.add(Calendar.YEAR, 10);
                KeyPairGeneratorSpec spec = new KeyPairGeneratorSpec.Builder(MyApplication.getInstance())
                        .setAlias(m_alias)
                        .setSubject(new X500Principal("CN="+m_alias))
                        .setSerialNumber(BigInteger.ONE)
                        .setStartDate(start.getTime())
                        .setEndDate(end.getTime())
                        .build();
                KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", "AndroidKeyStore");
                generator.initialize(spec);

                KeyPair keyPair = generator.generateKeyPair();

At runtime I got this exception :

java.security.ProviderException: Failed to generate self-signed certificate
             at android.security.keystore.AndroidKeyStoreKeyPairGeneratorSpi.generateKeyPair(AndroidKeyStoreKeyPairGeneratorSpi.java:504)
             at java.security.KeyPairGenerator$KeyPairGeneratorImpl.generateKeyPair(KeyPairGenerator.java:276)

....
 Caused by: java.lang.IllegalArgumentException: invalid date string: Unparseable date: "af`cab`hdedfGMT+00:00" (at offset 0)
             at com.android.org.bouncycastle.asn1.ASN1UTCTime.<init>(ASN1UTCTime.java:115)
             at com.android.org.bouncycastle.asn1.DERUTCTime.<init>(DERUTCTime.java:23)
             at com.android.org.bouncycastle.asn1.x509.Time.<init>(Time.java:67)

I searched about this issue and didn't find any possible solution, Please your help to fix the issue.

Notes : - Device : HTC M9 , Android v.6.0, build number : 3.35.401.12

• Date format examples : start Date : Sat Mar 12 23:10:08 GMT+03:00 2016 . End Date : Thu Mar 12 23:10:08 GMT+03:00 2026

Thanks in advance.