Here is a proposed release schedule for 0.19.0, the next major release of Bitcoin Core. Like for previous major releases I've aimed for a release 6 months after the last ( #14438).

2019-09-01 :heavy_check_mark: 
---------------
- Open Transifex translations for 0.19
- Soft translation string freeze (no large or unnecessary string changes until release)
- Finalize and close translations for 0.17

2019-09-15 :heavy_check_mark: 
---------------
- Feature freeze (bug fixes only until release)
- Translation string freeze (no more source language changes until release)

2019-10-01 :heavy_check_mark: 
---------------
- Split off `0.19` branch from `master`
- Start RC cycle, tag and release `0.19.0rc1`
- Start merging for 0.20 on master branch

2019-11-03 :heavy_check_mark:
---------------
- Release 0.19.0 final (aim)

If any specific dates or timeframes are a problem for you, let me know.

**Edit:** schedule was moved two months back on 2019-05-07, for reference, the old schedule was:
```
2019-11-01    Soft translation string freeze
2019-11-15    Feature freeze
2019-12-01    Split off 0.19 branch from master
2020-01-03    Release 0.19.0 final (aim)
```
if (setKeyPool.empty()) {
        return GetTime();
    }
    CKeyPool keypool;
    int64_t nIndex = *(setKeyPool.begin());
    if (!batch.ReadPool(nIndex, keypool)) {
        throw std::runtime_error(std::string(__func__) + ": read oldest key in keypool failed");
    }
    assert(keypool.vchPubKey.IsValid());
    return keypool.nTime;
}
int64_t CWallet::GetOldestKeyPoolTime()
{
    LOCK(cs_wallet);
    WalletBatch batch(*database);
    
    int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, batch);
    if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT)) {
        oldestKey = std::max(GetOldestKeyTimeInPool(setInternalKeyPool, batch), oldestKey);
        if (!set_pre_split_keypool.empty()) {
            oldestKey = std::max(GetOldestKeyTimeInPool(set_pre_split_keypool, batch), oldestKey);
        }
    }
    return oldestKey;
}
std::map<CTxDestination, CAmount> CWallet::GetAddressBalances(interfaces::Chain::Lock& locked_chain)