RedisCache : TTL updating on each hit instead of DAYS

I'm trying to update a field in a cache object on each hit. Similar to rate limiting with a different purpose.

My Cache Object:

@Getter@Setterpublic class CacheDO implements Serializable {    private static final long serialVersionUID = 1L;    int simCount;    Date date;    int viewCount;}

Cache Service:

public CacheDO updateCacheDO(boolean isDateToBeUpdated, Date date, int customerId, String customerIdStr) {   CacheDO cacheDO = new CacheDO();   byte[] valueInBytes = redisTemplate.getConnectionFactory().getConnection().get((customerIdStr).getBytes());   if(valueInBytes == null){      return addCacheDO(customerId, customerIdStr);   }   CacheDO deserialisedCacheDO;   try {      ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(valueInBytes);      deserialisedCacheDO = (CacheDO) new ClassLoaderObjectInputStream(CacheDO.class.getClassLoader(), byteArrayInputStream).readObject();   } catch (IOException | ClassNotFoundException e) {      LOGGER.error("Error deserializing object");      throw new RuntimeException(e.getMessage(),e);   }   cacheDO.setAbc(deserialisedCacheDO.getAbc());   if (isDateToBeUpdated) {      cacheDO.setDate(date);   } else {      cacheDO.setDate(deserialisedCacheDO.getDate());   }   cacheDO.setViewCount(deserialisedCacheDO.getViewCount() + 1);   Long ttl = redisTemplate.getConnectionFactory().getConnection().keyCommands().ttl(customerIdStr.getBytes(), TimeUnit.DAYS);   LOGGER.info("Updating cache for customer {} ", customerId);   redisTemplate.getConnectionFactory().getConnection().set(customerIdStr.getBytes(), SerializationUtils.serialize(cacheDO), Expiration.from(ttl, TimeUnit.DAYS), RedisStringCommands.SetOption.SET_IF_PRESENT);   return cacheDO;}

On every hit, ttl decreases by 1 instead of decreasing per day. I'm unable to figure out what could be done here, please help me understand my mistake.