> For the complete documentation index, see [llms.txt](https://orbcity.gitbook.io/orbcity/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://orbcity.gitbook.io/orbcity/building/upgrading-system/tier-up-evolution/time.md).

# Time

$$
Tier~~up\_{time}=t\_e~~\*\~tier\_{t}
$$

$$
t\_e=7\~days
$$

#### tier\_t

| Tier    | C->R   | R->E   | E->U   | U->L    |
| ------- | ------ | ------ | ------ | ------- |
| tier\_t | 1.2500 | 2.1875 | 5.4688 | 19.1406 |

Building owners can use time coupons to reduce the time it takes to tier up their building NFTs.

#### Tier Up Time (d)

| Tier    | C->R | R->E    | E->U     | U->L      |
| ------- | ---- | ------- | -------- | --------- |
| tier\_t | 8.75 | 15.3125 | 38.28125 | 133.98438 |

{% hint style="info" %}
The value of **t\_e** may be adjusted by governance.
{% endhint %}

{% hint style="info" %}
**Note: Please note that all figures are subject to change by governance.**
{% endhint %}