The Keeping Time quest can be obtained from Osiris at the Sundial on Mercury after completing the Matter of Time quest. This quest will also require you to obtain the quest Mars: Harmonizing the Obelisk. If you can't get this from Osiris, take the available quests, quit them, then interact with him again, and that should fix the issue.
Stage 1 - Mars: harmonization of the obelisk
For the first step, you need to complete the quest for the Mars Mine: Obelisk Attunement. You will need to collect 50 recovered BrayTech The Hive Enemies on Mars. This is very easy to do just outside of BrayTech, as there is a large amount of beehive spawning in the area. There is also a good chance that people will participate in the escalation protocol, which makes it even easier to do.
Once you have all 50, go to the Obelisk near the BrayTech spawn point and interact with it.
Stage 2 - Mars: Collection of light
Now that the Obelisk has been repaired and modified, you need to collect Light. Just like the first obelisk, kill the enemies with your abilities, your super and collect The Orbs of Light. Equip one or two mastered weapons to make sure plenty of Orbs of Light will drop, then kill any enemies you can find. Keep using Abilities and Supers to get your kills until you've fully charged your light charge to 100%.
When this is complete, return to the Obelisk to activate it and link it to the sundial.
Step 3 - Time lost and regained
For this stage, you must complete three Timelost weapon bounties. These can be obtained from Obelisks that you've ranked above Resonance Level 1. You'll need 10 Polarized Fractals and 3000 Glimmer to get one. Each Obelisk has three Timelost weapon bounties that become available at Resonance Ranks 1, 3, and 5.
This guide is under development.
