Most liquid honey granulates eventually and depending on the source of the honey it might take a month and it might take years. For example Maple blossom honey stays liquid much longer than other honey. If your honey granulates that does not mean it is going bad. You can put it in hot (37c) water to bring it back to liquid with minimal change in taste or aroma. It is important to leave it long enough so all the crystals are redissolved or the remaining crystals will “seed” the honey and it will immediately granulate again. Do not microwave or put honey in boiling water.