My Great-Grandfather During World War II. February 1945

My great-grandfather, Andrey Selyaskin, was a Soviet soldier, a sergeant in the 1381st Anti-Aircraft Artillery Regiment of the 3rd Guards Tank Army of the First Ukrainian Front, and a gunlayer on a 76.2 mm cannon.
In February, 1945, the 3rd Guards Tank Army participated in the Lower Silesian offensive. It was a Soviet offensive operation by the First Ukrainian Front (under Marshal Ivan Konev) to defeat the Nazi troops in Lower Silesia (Poland), reach the line of the Neisse River, and occupy a favorable position for upcoming offensives in the directions of Berlin, Dresden, and Prague. It took place between February 8 and 24, 1945.  [1] 
The 3rd Guards Tank Army began the offensive from its bridgehead in the area of Steinau on the 8th of February. [1] The enemy's forces [2] defending Breslau were surrounded by Soviet troops on the 15th of February.
In late February, several units of the 3rd Guards Tank Army were surrounded by German troops in the area of Lauban.
As the result of the Lower Silesian operation, the armies of the First Ukrainian Front surrounded a large German force [2] in Breslau, reached the Neisse River, and liberated a part of the Silesian industrial region, which had been very important for the economy of Nazi Germany.

[1]  Stewart's corrections started me thinking about the best way to state the dates.  After thinking about it, I preferred to say, "between February 8 and 24" for purely stylistic reasons.  When dealing with a range of dates, such a phrase as "between the 8th and the 24th of February" has started to sound too "wordy" [too many words] to me.  On the other hand, when dealing with only one date, a grammatical structure such as "on the 8th of February" sounds very good.  Also, the structure, "on the 8th of February" sounds more formal and scholarly than "on February 8."  

[2]  The word "group" doesn't sound right to me, unless it is used in connection with a particular German Army Group, such as "German Army Group Center."

My great-grandfather, Andrey Selyaskin, was a Soviet soldier, a sergeant in the 1381st Anti-Aircraft Artillery Regiment of the 3rd Guards Tank Army of the First Ukrainian Front, and a gunlayer on a 76.2 mm cannon.

In February, 1945, the 3rd Guards Tank Army participated in the Lower Silesian offensive. It was a Soviet offensive operation by the First Ukrainian Front (under Marshal Ivan Konev) to defeat the Nazi troops in Lower Silesia (Poland), reaching the line of the Neisse River and occupying a favorable position for upcoming offensives in the Berlin, Dresden and Prague directions. It took place between the 8th and the 24th of February 8 and 24, 1945.

The 3rd Guards Tank Army began the offensive from the bridgehead in the area of Steinau on the 8th of February 8. The Breslau enemy group was surrounded by Soviet troops on the 15th of February 15. In late February, several units of the 3rd Guards Tank Army were surrounded by German troops in the area of Lauban.

As the result of the Lower Silesian operation, the armies of the First Ukrainian Front surrounded a large German group in Breslau, reached the Neisse River, and liberated a part of the Silesian industrial region, which was very important for the economy of Nazi Germany.