DBにしろpandasにしろ時間管理だとこんな感じにするかな
pandasの使い方これで合ってたかは忘れたけど
https://colab.research.google.com/drive/1W6g9HLYOliL3i9Dc-t6lfnw4oxsTPh4K

today=datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)
df=pd.DataFrame([
{"名前":"Aさん","開始":"2022-05-04 07:00:00","終了":"2022-05-04 16:00:00","description":""},
{"名前":"Bさん","開始":None,"終了":None,"description":"有給"},
{"名前":"Aさん","開始":"2022-05-05 07:00:00","終了":"2022-05-05 16:00:00","description":""},
{"名前":"Bさん","開始":"2022-05-05 07:00:00","終了":"2022-05-05 17:00:00","description":""},
{"名前":"Aさん","開始":"2022-05-06 07:00:00","終了":"2022-05-06 17:00:00","description":""},
{"名前":"Cさん","開始":"2022-05-06 10:00:00","終了":"2022-05-06 12:00:00","description":"早退"},
{"名前":"Bさん","開始":"2022-05-06 08:00:00","終了":"2022-05-06 19:30:00","description":""},
{"名前":"Dさん","開始":f"{today:%Y}-{today:%m}-{today:%d} 08:00:00","終了":f"{today:%Y}-{today:%m}-{today:%d} 21:00:00","description":""},
])
df["開始"]=pd.to_datetime(df["開始"])
df["終了"]=pd.to_datetime(df["終了"])

#Bさんのみ
#df[df["名前"]=="Bさん"]

#２０２２年５月６日のAさんの出勤時刻
df[df["名前"]=="Aさん"][df["開始"].dt.date==datetime(2022,5,6).date()].iloc[0]["開始"]

#２０２２年５月５日以降のみ
#df[df["開始"]>datetime(2022,5,5)]

#２０２２年５月６日、９時から１１時に出勤する人のみ
#df[(df["開始"]>datetime(2022,5,6,9,0)) & (df["開始"]<datetime(2022,5,6,11,0))]

#現在仕事中の人のみ
#df[(df["開始"]>today) & (df["終了"]>_to_zone(_jst))] )