High-quality day care centers, nurseries, and preschools are bustling centers of activity where your child will find academic stimulation, physical activity, friends, and plenty of play. In the long term, they can play a very positive role in your child's personal development . That doesn't mean your child will initially be thrilled when they start attending organized childcare, though! Research indicates that it is entirely normal for securely-attached children — that is, essentially, those who have strong and loving bonds with their parents — to be clingy and to cry when you drop them off and pick them up, and even to let their caregivers at day care know they're not happy with their current situation. 
What folks in your neck of the woods say about settling into day care: Common sense or cultural legacy?
Being multicultural and multilingual, I thought it would be interesting to examine what kinds of advice parents in different countries receive in regard to helping their kids settle into day care. I looked at recommendations made by popular Australian, Belgian, and Serbian parenting websites. The common threads were as interesting as the diverging points.
The Australian advice, from the website Raising Children, focused on supporting children's emotional needs as they transition into day care. Parents can help their children by learning what the day care's routine is before the child starts attending, they say, and then copying the schedule as closely as possible. Children also greatly benefit from knowing more about both the environment they'll be in and the people who will be looking after them, so visit the day care center together with your child and learn about the carers or educators there. Talk about the day care and its carers at home, so your child becomes familiar with them. 
Their Belgian colleagues from Kiddo, meanwhile, focus on parental attitudes towards the transition, and point out that parents who feel insecure about their decision to have their child attend a certain setting are more likely to subconsciously pass this attitude onto their children. This is why it is important for preschools and day care centers to make sure parents have all the information they need, and to develop positive relationships with staff. During the initial transitional process, the site says, parents and children can attend together so they both get used to the new environment and feel secure within it. 
In Serbia, writers from a popular website that translates to "the best mother in the world", decided to target what not to do when your child starts attending day care. Don't sneak out of the day care without saying good bye, they warn, don't be offended if your child starts acting out after starting day care, and don't "interrogate" the people who care for your child or speak badly about them with your partner or friends — this will make your child feel like you don't have confidence in the day care. Don't stop the settling-in process by pulling your child out of day care, unless they get sick. Do start with shorter visits to the day care, and do begin following its routine at home before your child begins attending. 
So, who's right?
Helping your child settle in to day care: What does science say?
Research shows that a child's ability to settle into a new educational setting depends on many factors — their own personality and the quality of the setting included. Your attitudes as a parent do matter a great deal as well, however, and your child is more likely to transition successfully and thrive if you yourself feel positive about your child's day care attendance.  Having a positive and supportive attitude even increases your little one's academic progress .
Parents are, of course, much more likely to feel good about the prospect of their kid's day care attendance if they have confidence in the staff. This starts with choosing your child's day care with safety in mind; if you know your child is safe and happy while they're being cared for by others, you won't have any worries to pass on to your child. In this sense, the Belgian approach was right, while the Serbian approach is one I'd consider to be both right and wrong — any parent who is so frustrated with day care staff that they feel the need to bad-mouth them in front of their child or otherwise should probably be looking for a new day care center.
The commonly offered advice to adapt to the day care's routine ahead of time (by adjusting your meal and play times, for instance) also makes sense — it's often said that "children thrive on routine", but when you think about it, most humans are really creatures of habit, who feel safer and happier when they can predict what the short-term future will be like. This is also true for children, who will adapt better if they know what to expect. 
Once the child begins day care, this adaptation process continues with visits during which you're present, and then with shorter stays without you. The day care will begin to feel familiar and safe during this time, and if you take the time to gradually increase the length of time your child's spends there, research shows that day care attendance will not affect your bond with your child negatively. 
Your child will most likely also appreciate it if you describe when you'll be picking them up — at a certain time if they have a watch and know how to use it, or "after lunch" or "after afternoon play outside" if they aren't yet able to tell the time. After you pick your child up, spend some special one-on-one time with them, during which you can have fun and your little one can tell you about their day.