In most cases, correcting this discrepancy is very simple. First you need to determine whether the error is systemic: if the data for each day, week and month in one of the systems is always less than in the other, then the most likely cause of error is the absence or incorrect operation of one of the counters on certain pages. Compare reports by page: most likely, you will see that one of the counters does not take into account visits to certain pages.
If the error is “floating”, and the total data for the month is almost the same, you can pay attention to the settings of Google Analytics: go to the profile properties, pay attention to the time zone of the site:
There is a high probability that there will be an incorrect zone: Analytics often exposes "Pacific Time" even for profiles, during the creation of which we indicated Moscow. It is clear that the data will be distributed between the days incorrectly.
The time zone can be changed by editing the profile. However, please note: this setting is not available until you specify the country in the field above:
For Analytics accounts connected to AdWords accounts, the time zone change may not be available. In this case, you may need to temporarily disable integration (via Google support).
If you are not the administrator of your Analytics account, you can also estimate what time zone is displayed on the site. It is necessary to go to the section "Visits":
set the current date and look at the report by the hour (did you know that it is in Google Analytics?):
Data starts to arrive in Analytics in about an hour, so this report should already contain data for the previous hour (screenshot taken at about 4:00 pm). If the picture is different - there are problems with the time zone.
Finally, I want to mention that although using two systems to solve identical tasks is not very logical, Yandex.Metrica has opportunities unique to the free web analytics market: for example, quite recently Metric learned how to collect a heatmap