Getting baby to sleep through the night!

Her sleeping clock is all wrong! My wife and I are also not able to sleep because the baby’s clock is all wrong. This is our first kid, does this normally happen, or can it be fixed immediately? She is 4 months old, this has been happening for a week now. Can the clock just change on its own? She was never like this before. Help us and tell us what we can do please. We are desperately getting baby to sleep through the night, but we are hopeless and can’t think of what to do. Is it a phase would it pass as quickly as it came.