Hope this helps:
from this input timers-raw.json:
```
{
"timer-instance" : [ {
"name" : "",
"id" : 1,
"timer-id" : 0,
"activation-time" : {
"java.util.Date" : 1701170556010
},
"last-fire-time" : null,
"next-fire-time" : {
"java.util.Date" : 1701170736010
},
"delay" : 180000,
"period" : 0,
"repeat-limit" : -1,
"process-instance-id" : 1,
"session-id" : 2
} ]
}
```
```
jq '.["timer-instance"][] | .["activation-time"]["java.util.Date"]|=(./1000 | strflocaltime("%F %T"))|.["next-fire-time"]["java.util.Date"]|=(./1000 | strflocaltime("%F %T"))' timers-raw.json
{
"name": "",
"id": 1,
"timer-id": 0,
"activation-time": {
"java.util.Date": "2023-11-28 12:22:36"
},
"last-fire-time": null,
"next-fire-time": {
"java.util.Date": "2023-11-28 12:25:36"
},
"delay": 180000,
"period": 0,
"repeat-limit": -1,
"process-instance-id": 1,
"session-id": 2
}
```