**df**

```
         f
0   l2y_q1_eps_gg
1   l2y_q2_eps_gg
2   l2y_q3_eps_gg
3   l2y_q4_eps_gg
4   l1y_q1_eps_gg

```

**Goal**

```
         f          fr_date
0   l2y_q1_eps_gg   20190331
1   l2y_q2_eps_gg   20190630
2   l2y_q3_eps_gg   20190930
3   l2y_q4_eps_gg   20191231
4   l1y_q1_eps_gg   20200331
5   cy_q1_eps_gg    20210331

```

The value of `fr_date` column is the last day of each year of each quarter and the rule is like below and the type of fr\_date is int :

* l2y:2019
* l1y:2020
* cy:2021
* q1-q4: the last day of each quarter

Notice:

* the start pattern of `f` column is `l2y/l1y/cy`+ `q1/q2/q3/q4`.
* If the current year changes, the rule will change. For example ,if current year is 2022, then l2y→2020, l1y→2021, cy→2022.